Mitch Austin was a Manly United junior in Sydney, Australia. He was spotted by the scouts of Rotherham United in 2009 whilst on a tour of the UK with Manly United and was offered a scholarship with the youth academy.
After making 71 league appearances, in 2013, he joined Conference team Cambridge United. In 2014, he was loaned to Lincoln City to get more first team opportunities. But Cambridge soon recalled Austin, & declined Lincoln’s request for an extension to the loan. Though weeks later he signed for Brackley Town again on loan. On 31 January 2014, his loan was extended till March. On 13 September 2014, he made his professional debut for Cambridge United against Dagenham and Redbridge In May 2015, Cambridge United announced, that Austin was one out of 12 players, who would leave the club in the summer 2015 expressing his wish to return to Australia.
On 1 June 2015, Central Coast Mariners announced that they had signed Austin to a two-year contract. After making 23 appearances in the first year of his contract, Austin asked to terminate his second year and was released by Central Coast Mariners.
On 17 June 2016, Melbourne Victory confirmed the signing of Austin as a straight swap for winger Connor Pain. He made an outstanding start to his Victory career, earning Man of the Match honours in the club's pre-season friendly win over Juventus at the MCG. Austin suffered an anterior cruciate ligament injury in training in November 2017, ruling him out for several months. On 1 February 2018, Austin was selected to represent Melbourne Victory in the E-League's inaugural season, alongside Mouad Zwed, becoming one of a handful of professional football players to compete in e-sports as well.
Austin signed with Scottish Championship club Partick Thistle in July 2019 on a one year deal. Austin chose kit number 77 for the 2019/20 season. On 11 January 2020 Austin finally made his first team debut for The Jags after being injured since signing in July 2019. Austin left Thistle in March 2020 agreeing to leave the club during the Coronavirus pandemic, to return home to his family in Australia. In his 8 months at the club Austin spent the majority of his spell out injured on the sidelines, and therefore only made 2 appearances for The Jags, both from coming off the bench.
