Jack Carleton Duncan (born 19 April 1993) is an Australian goalkeeper who plays for A-League Men club Melbourne Victory.

In 2010 Duncan signed for A-League club Newcastle Jets from NSW Premier League side Sutherland Sharks.

[4] He made his professional debut in the 2011-12 A-League season on 19 November 2011, in a round 7 clash against Brisbane Roar.

[8] In June 2016, Duncan asked to be released from his second contracted year with Randers FC because there was no indication to him becoming first choice.

[13] On 9 June 2023, Duncan joined New Zealand A-League Men club Wellington Phoenix, to provide competition for Alex Paulsen after the departure of Oli Sail to Perth Glory.