Mitch Austin was born in Rochdale, Greater Manchester on 3 April 1991. He has a twin sister, named Brittany. His father is the Australian Rugby league & Union Player Greg Austin. Mitch left England at the age of eight when his father retired from playing professional rugby and moved the family back to Australia.
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.
In 2010, he joined Conference North team Stalybridge Celtic.
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. After the loan spell was over, 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 against Dagenham and Redbridge At the end of the 2014–15 season the club did not offer him a new deal when his contract expired.
In May 2015, Cambridge United announced, that Austin was one out of 12 players, who would leave the club in the summer 2015.
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.As of 31 October 2016