William John Dumaresq (25 February 1793 – 9 November 1868) was an English-born military officer, civil engineer, landholder and early Australian politician.

In 1815, he and Samuel Augustus Perry were entrusted with the task of removing and returning to Venice the four bronze Horses of St Mark that Napoleon had taken to Paris and installed atop the Arc de Triomphe du Carrousel.

[1] During his time as a public official, William Dumaresq was the sponsor of a major improvement in Sydney's water supply, Busby's Bore.

He is also credited with the design of the Commissariat Store in Brisbane[5] and a watch house in Sydney (later the Erskine Street Police Station).

[7][8][9] From 1830, Dumaresq was a magistrate of the Hyde Park Barracks Court of General Sessions, with Samuel Augustus Perry (his successor as Deputy Surveyor-General) and James Busby.

[16][17] William seems to have emerged from retirement into a more public role, only after the death of his more ambitious and temperamental brother, Henry Dumaresq, in 1838.

[20] He was defeated for the seat at the 1848 New South Wales colonial election by Donald McIntyre, but was re-elected in 1851 as the member for Counties of Phillip, Brisbane and Bligh.

Royal Staff Corps Served in the Peninsula, and Canada, and New South Wales Born xxv February MDCCXCII., died in November MDCCCLXVIII.

Dumaresq's Sydney home at Rose Bay, Tivoli House, although subsequently extended, still exists as a building of the Kambala School.

[29] He is also remembered by Dumaresq Reserve, a foreshore park in Rose Bay,[30] The land that he sold at Glebe is now a significant part of that inner suburb, and the heritage building Bidura is located upon one of the lots.

Dumaresq's land adjoined the original village on its north and east sides, and also came close to its southern edge.