Memorial plaque on the Memorial to Heroic Self Sacrifice, Postman's Park, London. Plaque designed by Royal Doulton.

Postman's Park is a park in the City of London, a short distance north of St Paul's Cathedral. Bordered by Little Britain, Aldersgate Street, King Edward Street and the site of the former head office of the General Post Office, it is one of the City of London's largest parks. Opened in 1880 on the site of the former churchyard and burial ground of St Botolph's Aldersgate church, it expanded over the next 20 years to incorporate the adjacent burial grounds of Christ Church Greyfriars and St Leonard, Foster Lane, as well as the site of housing demolished during the widening of Little Britain in 1880, the ownership of which became the subject of a lengthy dispute between the church authorities, the General Post Office, the Treasury, and the City Parochial Foundation.

The park takes its name from its popularity with workers at the nearby headquarters of the General Post Office, despite that building's closure in the early 20th century. A shortage of space for burials in London meant that corpses were often laid on the ground and covered over with soil, as a result of which Postman's Park's ground level is significantly higher than that of its surrounding streets.

In 1900, the park became the location for George Frederic Watts's Memorial to Heroic Self Sacrifice, intended as a memorial to ordinary people who died saving the lives of others and might otherwise have been forgotten, in the form of a loggia and long wall housing ceramic memorial tablets to be designed by William De Morgan. At the time of its opening, only four of the planned 120 memorial tablets were in place, with a further nine tablets added during Watts's lifetime. Following Watts's death in 1904, his wife Mary Watts (née Mary Fraser Tytler) took over the management of the project and oversaw the installation of a further 35 memorial tablets in the following four years, as well as a small monument to Watts. However, disillusioned with the new tile manufacturer Royal Doulton following De Morgan's retirement from the ceramic industry to become a novelist, and with her time and money increasingly occupied by the running of the Watts Gallery, Mary Watts lost interest in the project. Other than a single tablet added to the memorial in 1919, and four tablets added to the memorial in 1930–31, no further tablets were added in Mary Watts's lifetime.