Born in Birkenhead, South Australia, the son of former Port Adelaide captain John Quinn, Sr. and the older brother of dual Magarey Medallist Bob, Quinn showed aptitude for football from a young age, and standing 170 cm tall and built like a tank, Quinn made his South Australian National Football League (SANFL) debut for Port as a rover in 1928.

Quinn immediately made his mark, becoming a key member of the 1928 Port premiership team.

Quinn played 59 matches for Port in three seasons plus six for South Australia before finding himself unemployed in the wake of the Great Depression.

Quinn had attracted interest from Victorian Football League (VFL) clubs at the 1930 Adelaide Carnival with his performances for South Australia, and when Geelong offered Quinn employment with the Ford Motor Company, a club sponsor, as a machine operator,[2] Quinn leapt at the opportunity and transferred to Geelong for the 1931 VFL season.

Gaining the nickname "Maggie" for his Port Adelaide heritage, Quinn immediately proved a success in the VFL, being a key player in Geelong's 1931 premiership team and became a firm favorite with Geelong fans.