Thompson Square Conservation Area, Heritage precinct in Windsor, New South Wales, Australia

Thompson Square Conservation Area is a heritage site with colonial buildings arranged around a central grassed space with mature trees. The precinct is bounded by four streets and includes structures such as the Macquarie Arms Hotel and Georgian-style cottages.

Governor Macquarie's 1811 tour of the district led him to grant Richard Fitzgerald a large allotment in the square on condition he build a two-storey brick or stone inn; the Macquarie Arms Hotel opened in 1815. The surrounding Georgian buildings followed: the Doctor's House site was leased as the Freemason's Arms in 1819, and the Hawkesbury Museum building is claimed to date from about 1843. The precinct was added to the New South Wales State Heritage Register on 2 April 1999.

The square's name honours Andrew Thompson, an early Hawkesbury settler and magistrate. The Pioneer Families Bicentennial Memorial in the reserve features an anchor, symbolising the river's role in the town's history, and a plaque listing many early family names.

George Street cuts diagonally through the square and drops into a cutting for the Putty Road, so cross with care where the two meet. The turfed reserve is ringed by George, Bridge and The Terrace, letting you walk a loop past the Doctor's House, the Macquarie Arms Hotel and the Hawkesbury Museum. Look for the hoop pine above the cutting, the last of the square's 19th-century plantings.

A single old hoop pine (Araucaria cunninghamii) above the Putty Road cutting is said to be the last survivor of the square's mid-to-late 19th-century plantings. Norfolk Island pines once stood on the western side outside the Macquarie Arms Hotel and in front of the Fitzgerald wall, but they and native fig trees were removed after complaints about public indecency by people leaving the hotel.