John Brown Watt (16 May 1826 – 28 September 1897) was a Scottish-born Australian businessman, banker, and politician.

[1] Watt was appointed a member of the New South Wales Legislative Council in September 1861,[4] but resigned on leaving for England in March 1866.

He was the Commissioner for New South Wales at the International Exhibitions of Philadelphia (1876), Paris (1878), Sydney (1879), Amsterdam (1883) and at Calcutta (1883–84).

In 1884, he was invited to the United Kingdom to join the Executive Committee of the Imperial Federation League.

Another son, Ernest Watt, became the father-in-law of Sir Laurence Whistler Street when he married Ernest's daughter Susan Gai Watt, herself the first female chair of the Eastern Sydney Health Service (now amalgamated with Illawarra).