Willie Dunn Sr. (19 August 1821 – 14 February 1878) was a Scottish professional golfer who played during the mid-to-late 19th century.

[1] Willie Dunn was born in Musselburgh, Scotland, on 19 August 1821.

[2] Along with his twin brother, Jamie, he played in many challenge matches between 1840–60.

Dunn apprenticed under the Gourlay family and was keeper of the greens at Blackheath until 1864 when he returned to the Thistle Golf Club at Leith Links.

[3] Dunn placed seventh in the 1861 Open Championship, carding consistent rounds of 61-59-60=180.