Irwin Thomas (born Irwin Thomas Whittridge; 6 January 1971) is an American-born Australian singer-songwriter and guitarist. He performs professionally using the stage name Jack Jones from when he was the lead vocalist-guitarist in the band Southern Sons (1990–1996).

His other bands collaborations include Electric Mary, She Said Yes and Ahmet Zappa. He is known for his collaborations with John Farnham and Rick Price.

He released his debut solo album, The Evolution of Irwin Thomas, in 2002.