Jack Callahan is a fictional character from the Australian soap opera Neighbours, played by Andrew Morley. The actor was cast in late 2015 and landed the regular role of Jack. Morley had previously played Spencer Harrington in fellow soap opera Home and Away for two years. He made his first appearance during the episode broadcast on 4 April 2016. The character departed on 30 March 2018, but Morley later reprised the role and returned on 26 February 2020, as part of the show's 35th anniversary celebrations.

Erinsborough is a fictional suburb of Melbourne, Australia, where the soap opera Neighbours is set, focusing on the domestic and professional lives of the people who live and work there. Neighbours primarily centers on the residents of Ramsay Street and other Erinsborough locations, most prominently those situated within the Lassiters complex. Erinsborough is a loose anagram of Neighbours.