William Minchin (1774–26 March 1821) was an Irish-born British army officer.

He returned to England with the New South Wales Corps, now the 102nd Regiment of Foot, in 1810.

He served with the regiment on Guernsey, Bermuda, during the American War of 1812, Halifax and New Brunswick.

In August 1817 Minchin sold his commission and retired to New South Wales.

The Sydney suburb of Minchinbury is named after Minchin, who was granted property in the area in 1819.