The site is one of Australia's oldest parks to be continuously set aside as open space for public use in an urban context.

The space which is now Wynyard Park was originally the parade ground of the first military barracks established shortly after the European colonisation of Sydney in 1788.

Like similar squares in England its use was confined to residents who held keys to the gates, although by 1907 the American trend of removing fences around parks had been copied here.

Colonial Architect Mortimer Lewis (1835-1849) and the Director of the Sydney Botanic Gardens Charles Moore (1848-1896), influenced the design of the park.

[1] At the northern end of the park is a statue by Giovanni Fontana from 1890 of the Reverend J. D. Lang, the Presbyterian minister and controversialist, lived at Wynyard Square and was responsible for the erection of the Scots Church in 1826.