Memorial plaque on the Memorial to Heroic Self Sacrifice, Postman's Park, London. Plaque designed by William De Morgan.

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.