Wikipedia:WikiProject Ohio/Articles/O
Appearance
- O'Bleness Memorial Hospital
- O'Bryonville, Cincinnati, Ohio
- O'Connor's Landing
- O'Neil's
- O'Shaughnessy Dam (Ohio)
- O. C. Barber
- O. C. Barber Barn No. 1
- O. C. Barber Colt Barn
- O. C. Barber Creamery
- O. C. Barber Machine Barn
- O. C. Barber Piggery
- O. J. Mayo
- O. J. McDuffie
- O. O. McIntyre
- Oak Harbor High School (Ohio)
- Oak Harbor, Ohio
- Oak Hill Cottage
- Oak Hill High School (Ohio)
- Oak Hill, Ohio
- Oak Hills High School (Cincinnati, Ohio)
- Oak Hills Local School District
- Oak Openings Preserve Metropark
- Oak Run Township, Madison County, Ohio
- Oakland & Northwood Avenue Area
- Oakland Center for the Arts
- Oakley, Ohio
- Oakwood City School District
- Oakwood High School
- Oakwood, Cuyahoga County, Ohio
- Oakwood, Montgomery County, Ohio
- Oakwood, Paulding County, Ohio
- Oberlin College
- Oberlin Conservatory of Music
- Oberlin Heritage Center
- Oberlin High School (Ohio)
- Oberlin Steel
- Oberlin, Ohio
- Obetz, Ohio
- Observatory Historic District (Cincinnati, Ohio)
- Oceola, Ohio
- Octa, Ohio
- Odd Fellows' Cemetery Mound (Ohio)
- Odd Fellows Hall (Sandusky, Ohio)
- Odyssey (fictional town)
- Oesterlein Machine Company-Fashion Frocks Inc. Complex (Cincinnati, Ohio)
- Ohayocon
- OHDELA
- Ohio
- Ohio's 10th congressional district
- Ohio's 11th congressional district
- Ohio's 11th congressional district special election, 2008
- Ohio's 12th congressional district
- Ohio's 13th congressional district
- Ohio's 13th congressional district election, 2006
- Ohio's 14th congressional district
- Ohio's 15th congressional district
- Ohio's 16th congressional district
- Ohio's 17th congressional district
- Ohio's 18th congressional district
- Ohio's 19th congressional district
- Ohio's 1st congressional district
- Ohio's 20th congressional district
- Ohio's 21st congressional district
- Ohio's 22nd congressional district
- Ohio's 23rd congressional district
- Ohio's 24th congressional district
- Ohio's 2nd congressional district
- Ohio's 2nd congressional district election, 2006
- Ohio's 2nd congressional district special election, 2005
- Ohio's 3rd congressional district
- Ohio's 4th congressional district
- Ohio's 5th congressional district
- Ohio's 5th congressional district special election, 2007
- Ohio's 6th congressional district
- Ohio's 7th congressional district
- Ohio's 8th congressional district
- Ohio's 9th congressional district
- Ohio's At-large congressional district
- Ohio's congressional districts
- Ohio-Pennsylvania League
- Ohio (1953 song)
- Ohio (album)
- Ohio (Come Back to Texas)
- Ohio (Crosby, Stills, Nash & Young song)
- Ohio (disambiguation)
- Ohio 10th district democratic primary election 2008
- Ohio Adjutant General's Department
- Ohio Agricultural Research and Development Center
- Ohio Air National Guard
- Ohio and Erie Canal
- Ohio and Mississippi Railway
- Ohio and Pennsylvania Railroad (1995-present)
- Ohio Apportionment Board
- Ohio Army National Guard
- Ohio Art Company
- Ohio Arts Council
- Ohio Athletic Conference
- Ohio Attorney General
- Ohio Attorney General elections
- Ohio Ballot Board
- Ohio Bell
- Ohio Board of Regents
- Ohio Bobcats
- Ohio Bobcats football
- Ohio Bobcats men's basketball
- Ohio Brush Creek
- Ohio Bureau of Criminal Identification and Investigation
- Ohio Bureau of Workers' Compensation
- Ohio Business College
- Ohio Cardinal Conference
- Ohio Caverns
- Ohio census statistical areas
- Ohio Central College
- Ohio Central Railroad System
- Ohio Christian University
- Ohio Citizen Action
- Ohio City, Cleveland
- Ohio City, Ohio
- Ohio Classic
- Ohio College of Dental Surgery
- Ohio College of Podiatric Medicine
- Ohio Company
- Ohio Company of Associates
- Ohio Constitution
- Ohio Country
- Ohio county government
- Ohio Court of Claims
- Ohio Credit Union System
- Ohio Cup
- Ohio Cup (1989-1996)
- Ohio Cup (2008-Present)
- Ohio Democratic Party
- Ohio Democratic primary, 2008
- Ohio Department of Aging
- Ohio Department of Job and Family Services
- Ohio Department of Natural Resources
- Ohio Department of Transportation
- Ohio Derby
- Ohio District (LCMS)
- Ohio District Courts of Appeal
- Ohio Dominican University
- Ohio Eleventh District Court of Appeals
- Ohio estate tax
- Ohio Expo Center Coliseum
- Ohio Federation of Teachers
- Ohio Fireworks Derecho
- Ohio Gang
- Ohio General Assembly
- Ohio Glory
- Ohio Grade Level Chess Championships
- Ohio Graduation Test
- Ohio gubernatorial election, 1998
- Ohio gubernatorial election, 2006
- Ohio gubernatorial election, 2010
- Ohio gubernatorial elections
- Ohio Hi-Point Career Center
- Ohio High School Athletic Association
- Ohio high school athletic conferences
- Ohio High School Speech League
- Ohio highway sniper attacks
- Ohio Historical Society
- Ohio House of Representatives
- Ohio House of Representatives membership, 125th General Assembly
- Ohio House of Representatives membership, 126th General Assembly
- Ohio House of Representatives, 58th District
- Ohio House of Representatives, 80th District
- Ohio House of Representatives, 82nd District
- Ohio Hub
- Ohio in the American Civil War
- Ohio Institute of Health Careers
- Ohio Institute of Photography and Technology
- Ohio Institute of Technology
- Ohio Junior Blue Jackets
- Ohio Kings Island Open
- Ohio Lands
- Ohio Legislative Black Caucus
- Ohio lieutenant gubernatorial elections
- Ohio Life Insurance and Trust Company
- Ohio Light Opera
- Ohio locations by per capita income
- Ohio Lottery
- Ohio Migrant Education Center
- Ohio Military Reserve
- Ohio National Guard
- Ohio National Guard Armory (Cincinnati, Ohio)
- Ohio Naval Militia
- Ohio Northern University
- Ohio Open
- Ohio Patriot Act
- Ohio Penitentiary
- Ohio Planning Conference
- Ohio Players
- Ohio preteen murders
- Ohio Public Library Information Network (OPLIN)
- Ohio Railway Museum
- Ohio Regional Campus Conference
- Ohio Renaissance Festival
- Ohio Republican Party
- Ohio Republican primary, 2008
- Ohio Resource Center
- Ohio Revised Code
- Ohio River
- Ohio River flood of 1937
- Ohio River Valley AVA
- Ohio Roller Girls
- Ohio Savings Plaza
- Ohio School for the Deaf
- Ohio Scientific
- Ohio Secretary of State
- Ohio Secretary of State elections
- Ohio Senate
- Ohio Senate membership, 125th General Assembly
- Ohio Seventh District Court of Appeals
- Ohio Softball Field
- Ohio Stadium
- Ohio State Auditor
- Ohio State Auditor elections
- Ohio State Board of Education
- Ohio State Buckeyes
- Ohio State Buckeyes baseball
- Ohio State Buckeyes football
- Ohio State Fair
- Ohio State Highway Patrol
- Ohio State Issue 1 (2004)
- Ohio State Limited
- Ohio State Penitentiary
- Ohio State Reformatory
- Ohio State Route 1
- Ohio State Route 10
- Ohio State Route 10 (1923)
- Ohio State Route 100
- Ohio State Route 101
- Ohio State Route 102 (1923)
- Ohio State Route 103
- Ohio State Route 104
- Ohio State Route 105
- Ohio State Route 107
- Ohio State Route 108
- Ohio State Route 109
- Ohio State Route 11
- Ohio State Route 11 (1923)
- Ohio State Route 110
- Ohio State Route 111
- Ohio State Route 112 (1923)
- Ohio State Route 113
- Ohio State Route 114
- Ohio State Route 115
- Ohio State Route 116
- Ohio State Route 117
- Ohio State Route 118
- Ohio State Route 119
- Ohio State Route 12
- Ohio State Route 120
- Ohio State Route 121
- Ohio State Route 122
- Ohio State Route 123
- Ohio State Route 124
- Ohio State Route 124 (1923)
- Ohio State Route 125
- Ohio State Route 125 (1923)
- Ohio State Route 126
- Ohio State Route 128
- Ohio State Route 129
- Ohio State Route 13
- Ohio State Route 130
- Ohio State Route 130 (1923)
- Ohio State Route 131
- Ohio State Route 132
- Ohio State Route 133
- Ohio State Route 134
- Ohio State Route 135
- Ohio State Route 136
- Ohio State Route 137
- Ohio State Route 138
- Ohio State Route 139
- Ohio State Route 14
- Ohio State Route 140
- Ohio State Route 141
- Ohio State Route 142
- Ohio State Route 143
- Ohio State Route 144
- Ohio State Route 146
- Ohio State Route 149
- Ohio State Route 15
- Ohio State Route 15 (1923)
- Ohio State Route 150
- Ohio State Route 151
- Ohio State Route 152
- Ohio State Route 153
- Ohio State Route 154
- Ohio State Route 159
- Ohio State Route 16
- Ohio State Route 16 (1923)
- Ohio State Route 160
- Ohio State Route 161
- Ohio State Route 162
- Ohio State Route 163
- Ohio State Route 164
- Ohio State Route 165
- Ohio State Route 166
- Ohio State Route 167
- Ohio State Route 168
- Ohio State Route 169
- Ohio State Route 17
- Ohio State Route 17 (1923)
- Ohio State Route 170
- Ohio State Route 171
- Ohio State Route 172
- Ohio State Route 173
- Ohio State Route 176
- Ohio State Route 18
- Ohio State Route 180
- Ohio State Route 180 (1923)
- Ohio State Route 181
- Ohio State Route 183
- Ohio State Route 184
- Ohio State Route 185
- Ohio State Route 186
- Ohio State Route 188
- Ohio State Route 19
- Ohio State Route 19 (1923)
- Ohio State Route 193
- Ohio State Route 198
- Ohio State Route 199
- Ohio State Route 2
- Ohio State Route 20 (1923)
- Ohio State Route 202
- Ohio State Route 203
- Ohio State Route 204
- Ohio State Route 205
- Ohio State Route 207
- Ohio State Route 208
- Ohio State Route 21
- Ohio State Route 21 (1923)
- Ohio State Route 213
- Ohio State Route 217
- Ohio State Route 218
- Ohio State Route 22 (1923)
- Ohio State Route 220
- Ohio State Route 221
- Ohio State Route 223 (1923)
- Ohio State Route 226
- Ohio State Route 228
- Ohio State Route 231
- Ohio State Route 232
- Ohio State Route 232 (1923)
- Ohio State Route 233
- Ohio State Route 235
- Ohio State Route 237
- Ohio State Route 238
- Ohio State Route 239
- Ohio State Route 241
- Ohio State Route 242
- Ohio State Route 243
- Ohio State Route 246
- Ohio State Route 247
- Ohio State Route 25
- Ohio State Route 25 (1923)
- Ohio State Route 251
- Ohio State Route 252
- Ohio State Route 253
- Ohio State Route 254
- Ohio State Route 257
- Ohio State Route 26
- Ohio State Route 261
- Ohio State Route 265
- Ohio State Route 266
- Ohio State Route 267
- Ohio State Route 269
- Ohio State Route 27 (1923)
- Ohio State Route 273
- Ohio State Route 274
- Ohio State Route 279
- Ohio State Route 28
- Ohio State Route 28 (1923)
- Ohio State Route 281
- Ohio State Route 283
- Ohio State Route 287
- Ohio State Route 288
- Ohio State Route 289
- Ohio State Route 29
- Ohio State Route 292
- Ohio State Route 293
- Ohio State Route 294
- Ohio State Route 297
- Ohio State Route 3
- Ohio State Route 30 (1923)
- Ohio State Route 300
- Ohio State Route 303
- Ohio State Route 304
- Ohio State Route 305
- Ohio State Route 306
- Ohio State Route 307
- Ohio State Route 309
- Ohio State Route 31
- Ohio State Route 31 (1923)
- Ohio State Route 313
- Ohio State Route 314
- Ohio State Route 315
- Ohio State Route 317
- Ohio State Route 319
- Ohio State Route 32
- Ohio State Route 320
- Ohio State Route 323
- Ohio State Route 324
- Ohio State Route 325
- Ohio State Route 327
- Ohio State Route 328
- Ohio State Route 329
- Ohio State Route 33 (1923)
- Ohio State Route 330
- Ohio State Route 331
- Ohio State Route 332
- Ohio State Route 334
- Ohio State Route 335
- Ohio State Route 338
- Ohio State Route 339
- Ohio State Route 34
- Ohio State Route 344
- Ohio State Route 348
- Ohio State Route 349
- Ohio State Route 35 (1923)
- Ohio State Route 350
- Ohio State Route 353
- Ohio State Route 355
- Ohio State Route 357
- Ohio State Route 36 (1923)
- Ohio State Route 364
- Ohio State Route 365
- Ohio State Route 366
- Ohio State Route 368
- Ohio State Route 369
- Ohio State Route 37
- Ohio State Route 370
- Ohio State Route 371
- Ohio State Route 372
- Ohio State Route 373
- Ohio State Route 378
- Ohio State Route 38
- Ohio State Route 380
- Ohio State Route 383
- Ohio State Route 385
- Ohio State Route 39
- Ohio State Route 4
- Ohio State Route 40 (1923)
- Ohio State Route 41
- Ohio State Route 412
- Ohio State Route 42 (1923)
- Ohio State Route 420
- Ohio State Route 423
- Ohio State Route 424
- Ohio State Route 43
- Ohio State Route 430
- Ohio State Route 435
- Ohio State Route 44
- Ohio State Route 444
- Ohio State Route 446
- Ohio State Route 45
- Ohio State Route 450
- Ohio State Route 46
- Ohio State Route 47
- Ohio State Route 47 (1923)
- Ohio State Route 48
- Ohio State Route 48 (1923)
- Ohio State Route 49
- Ohio State Route 49 (1923)
- Ohio State Route 49A
- Ohio State Route 5
- Ohio State Route 5 (1923)
- Ohio State Route 500
- Ohio State Route 501
- Ohio State Route 502
- Ohio State Route 503
- Ohio State Route 506
- Ohio State Route 507
- Ohio State Route 508
- Ohio State Route 51
- Ohio State Route 51 (1923)
- Ohio State Route 510
- Ohio State Route 511
- Ohio State Route 515
- Ohio State Route 517
- Ohio State Route 518
- Ohio State Route 519
- Ohio State Route 52 (1923)
- Ohio State Route 521
- Ohio State Route 522
- Ohio State Route 523
- Ohio State Route 526
- Ohio State Route 527
- Ohio State Route 528
- Ohio State Route 53
- Ohio State Route 531
- Ohio State Route 532
- Ohio State Route 533
- Ohio State Route 534
- Ohio State Route 535
- Ohio State Route 54
- Ohio State Route 540
- Ohio State Route 545
- Ohio State Route 546
- Ohio State Route 55
- Ohio State Route 550
- Ohio State Route 551
- Ohio State Route 552
- Ohio State Route 553
- Ohio State Route 554
- Ohio State Route 558
- Ohio State Route 559
- Ohio State Route 56
- Ohio State Route 561
- Ohio State Route 562
- Ohio State Route 566
- Ohio State Route 567
- Ohio State Route 568
- Ohio State Route 57
- Ohio State Route 571
- Ohio State Route 575
- Ohio State Route 576
- Ohio State Route 579
- Ohio State Route 58
- Ohio State Route 582
- Ohio State Route 585
- Ohio State Route 586
- Ohio State Route 587
- Ohio State Route 588
- Ohio State Route 589
- Ohio State Route 59
- Ohio State Route 590
- Ohio State Route 595
- Ohio State Route 598
- Ohio State Route 6 (1923)
- Ohio State Route 60
- Ohio State Route 600
- Ohio State Route 601
- Ohio State Route 603
- Ohio State Route 604
- Ohio State Route 605
- Ohio State Route 607
- Ohio State Route 608
- Ohio State Route 609
- Ohio State Route 61
- Ohio State Route 611
- Ohio State Route 613
- Ohio State Route 615
- Ohio State Route 616
- Ohio State Route 617
- Ohio State Route 618
- Ohio State Route 619
- Ohio State Route 62 (1923)
- Ohio State Route 621
- Ohio State Route 625
- Ohio State Route 626
- Ohio State Route 627
- Ohio State Route 63
- Ohio State Route 63 (1923)
- Ohio State Route 630
- Ohio State Route 632
- Ohio State Route 633
- Ohio State Route 635
- Ohio State Route 638
- Ohio State Route 64
- Ohio State Route 640
- Ohio State Route 643
- Ohio State Route 644
- Ohio State Route 65
- Ohio State Route 650
- Ohio State Route 657
- Ohio State Route 66
- Ohio State Route 660
- Ohio State Route 661
- Ohio State Route 662
- Ohio State Route 664
- Ohio State Route 665
- Ohio State Route 669
- Ohio State Route 67
- Ohio State Route 671
- Ohio State Route 676
- Ohio State Route 678
- Ohio State Route 681
- Ohio State Route 682
- Ohio State Route 683
- Ohio State Route 684
- Ohio State Route 687
- Ohio State Route 689
- Ohio State Route 69 (1923)
- Ohio State Route 690
- Ohio State Route 696
- Ohio State Route 697
- Ohio State Route 698
- Ohio State Route 7
- Ohio State Route 70 (1923)
- Ohio State Route 700
- Ohio State Route 701
- Ohio State Route 705
- Ohio State Route 707
- Ohio State Route 708
- Ohio State Route 709
- Ohio State Route 711
- Ohio State Route 714
- Ohio State Route 715
- Ohio State Route 716
- Ohio State Route 718
- Ohio State Route 719
- Ohio State Route 72
- Ohio State Route 720
- Ohio State Route 721
- Ohio State Route 722
- Ohio State Route 723
- Ohio State Route 724
- Ohio State Route 725
- Ohio State Route 726
- Ohio State Route 728
- Ohio State Route 73
- Ohio State Route 732
- Ohio State Route 735
- Ohio State Route 736
- Ohio State Route 739
- Ohio State Route 74 (1923)
- Ohio State Route 741
- Ohio State Route 745
- Ohio State Route 746
- Ohio State Route 749
- Ohio State Route 750
- Ohio State Route 752
- Ohio State Route 757
- Ohio State Route 761
- Ohio State Route 762
- Ohio State Route 763
- Ohio State Route 764
- Ohio State Route 767
- Ohio State Route 768
- Ohio State Route 77 (1923)
- Ohio State Route 770
- Ohio State Route 772
- Ohio State Route 774
- Ohio State Route 775
- Ohio State Route 776
- Ohio State Route 778
- Ohio State Route 78
- Ohio State Route 781
- Ohio State Route 785
- Ohio State Route 788
- Ohio State Route 79
- Ohio State Route 790
- Ohio State Route 792
- Ohio State Route 793
- Ohio State Route 794
- Ohio State Route 795
- Ohio State Route 797
- Ohio State Route 799
- Ohio State Route 8
- Ohio State Route 80 (1923)
- Ohio State Route 800
- Ohio State Route 807
- Ohio State Route 81
- Ohio State Route 81 (1923)
- Ohio State Route 814
- Ohio State Route 82
- Ohio State Route 821
- Ohio State Route 822
- Ohio State Route 823
- Ohio State Route 83
- Ohio State Route 833
- Ohio State Route 835
- Ohio State Route 84
- Ohio State Route 844
- Ohio State Route 85
- Ohio State Route 850
- Ohio State Route 852
- Ohio State Route 86
- Ohio State Route 87
- Ohio State Route 872
- Ohio State Route 88
- Ohio State Route 89
- Ohio State Route 9
- Ohio State Route 9 (1923)
- Ohio State Route 91
- Ohio State Route 93
- Ohio State Route 94
- Ohio State Route 95
- Ohio State Route 96
- Ohio State Route 97
- Ohio State Route 98
- Ohio State Route 99
- Ohio State School for the Blind
- Ohio State Treasurer
- Ohio State Treasurer elections
- Ohio State University
- Ohio State University Agricultural Technical Institute
- Ohio State University Airport
- Ohio State University Golf Club
- Ohio State University Press
- Ohio State University, Lima Campus
- Ohio State University, Mansfield Campus
- Ohio State University, Newark Campus
- Ohio Statehouse
- Ohio Supercomputer Center
- Ohio Supreme Court elections
- Ohio Swarm
- Ohio Theater (Cleveland)
- Ohio Theatre (Columbus)
- Ohio Theatre (Loudonville)
- Ohio Theatre (Mansfield)
- Ohio to Erie Trail
- Ohio Township, Clermont County, Ohio
- Ohio Township, Gallia County, Ohio
- Ohio Township, Monroe County, Ohio
- Ohio Township, Ohio
- Ohio Turnpike
- Ohio Union
- Ohio University
- Ohio University-Chillicothe
- Ohio University Aquatic Center
- Ohio University Press
- Ohio University Southern Campus
- Ohio Valley Athletic Conference
- Ohio Valley Career and Technical Center
- Ohio Valley Electric Railway
- Ohio Village
- Ohio Wesleyan Female College
- Ohio Wesleyan University
- Ohio Wesleyan University Library
- Ohio Western Reserve National Cemetery
- Ohio wine
- Ohio Women's Hall of Fame
- Ohio Women's Methodist Seminary
- Ohio Xoggz
- OhioLINK
- Okay Lindon
- Okeana, Ohio
- Okolona, Ohio
- Old Brooklyn
- Old College Hill Post Office (Cincinnati, Ohio)
- Old Fort High School
- Old Fort, Ohio
- Old Gothic Barns (Cincinnati, Ohio)
- Old Grandma Hardcore
- Old Jewish Cemetery, Cincinnati
- Old Meigs County Courthouse and Chester Academy
- Old North Columbus
- Old North Dayton, Dayton, Ohio
- Old Oaks Historic District
- Old Piqua High School
- Old St. Joseph's Cemetery
- Old St. Mary's Church
- Old Stone Church (Cleveland, Ohio)
- Old Trail School
- Old Washington, Ohio
- Old West End
- Olde Towne East
- Olde West Chester, Ohio
- Olentangy High School (Lewis Center, Ohio)
- Olentangy Liberty High School (Powell, Ohio)
- Olentangy Local School District (Delaware County, Ohio)
- Olentangy Orange High School (Lewis Center, Ohio)
- Olentangy Park
- Olentangy River
- Olentangy River Wetland Research Park
- Olentangy, Ohio
- Olga Rudge
- Olin's Covered Bridge
- Olive Township, Meigs County, Ohio
- Olive Township, Noble County, Ohio
- Olive Township, Ohio
- Oliver Edwin Baker
- Oliver Ocasek
- Oliver P. Bolton
- Oliver Township, Adams County, Ohio
- Olivesburg, Ohio
- Ollie Cline
- Olmsted Falls City School District
- Olmsted Falls High School
- Olmsted Falls, Ohio
- Olmsted Township, Cuyahoga County, Ohio
- Olney Friends School
- OM Group
- Omar D. Conger
- Omarosa Manigault-Stallworth
- Omensetter's Luck
- OMNOVA Solutions
- Onaway (RTA Rapid Transit station)
- One Cleveland Center
- One Columbus Center
- One Life Crew
- One Nationwide Plaza
- One SeaGate
- Online Computer Library Center
- ONN
- Ontario High School (Ohio)
- Ontario Local School District
- Ontario, Ohio
- Oorang Indians
- Open Door Christian School (Elyria, Ohio)
- Opera Cleveland
- Orange High School (Ohio)
- Orange Township, Ashland County, Ohio
- Orange Township, Carroll County, Ohio
- Orange Township, Delaware County, Ohio
- Orange Township, Hancock County, Ohio
- Orange Township, Meigs County, Ohio
- Orange Township, Ohio
- Orange Township, Shelby County, Ohio
- Orange, Ohio
- Orangeville, Ohio
- Oregon Historic District
- Oregon, Ohio
- Oregonia, Ohio
- Oreton, Ohio
- Orient, Ohio
- Origins Game Fair
- Orland Smith
- Orlando Metcalfe Poe
- Orlando Pace
- Ormsby M. Mitchel
- Orra E. Monnette
- Orrville City School District
- Orrville High School
- Orrville, Ohio
- Orton Ceramic Foundation
- Orville D. Merillat
- Orville James Victor
- Orwell Township, Ashtabula County, Ohio
- Orwell, Ohio
- Osborn Engineering
- Osborn v. Bank of the United States
- Osborn, Ohio
- Oscar Apfel
- Oscar F. Moore
- Oscar Grimes
- Oscar Lawrence Jackson
- Oscnet
- Osee M. Hall
- Osgood Company
- Osgood, Ohio
- Osnaburg Local School District
- Osnaburg Township, Stark County, Ohio
- Ostrander, Ohio
- Ostrich fern
- OSU Ice Arena
- Othniel Looker
- Othniel Looker House (Harrison, Ohio)
- Otho F. Strahl
- Otis Harlan
- Otsego High School
- Ottawa-Glandorf High School (Ottawa, Ohio)
- Ottawa - Glandorf Local School District, Putnam County, Ohio
- Ottawa County, Ohio
- Ottawa Hills High School (Ohio)
- Ottawa Hills, Ohio
- Ottawa River (Auglaize River)
- Ottawa River (Lake Erie)
- Ottawa Township, Putnam County, Ohio
- Ottawa, Ohio
- Ottawa, Toledo, Ohio
- Otterbein College
- Otterbein, Ohio
- Otto Neu
- Ottoville High School
- Ottoville, Ohio
- Otway, Ohio
- Our Lady of Mercy High School (Cincinnati, Ohio)
- Our Lady of the Elms High School
- Our Lady of the Visitation School
- Outhwaite Homes
- Over-the-Rhine
- Over the Rhine
- OverDrive, Inc.
- Overhoff Technology
- Overland Automobile
- Overpeck, Ohio
- Owen Magnetic
- Owens-Illinois
- Owens Community College
- Owens Corning
- Owensville, Ohio
- Ox-Cart Library
- Oxford Female Institute (Oxford, Ohio)
- Oxford Railroad Depot and Junction House
- Oxford Railroad Depot and Junction House (Oxford, Ohio)
- Oxford Township, Butler County, Ohio
- Oxford Township, Coshocton County, Ohio
- Oxford Township, Delaware County, Ohio
- Oxford Township, Erie County, Ohio
- Oxford Township, Guernsey County, Ohio
- Oxford Township, Ohio
- Oxford Township, Tuscarawas County, Ohio
- Oxford, Ohio
- Ozro J. Dodds