Langerak signed his first professional contract in February 2007, with A-League club Melbourne Victory. Soon after he was sent on loan to South Melbourne for the remainder of the 2007 Victorian Premier League season, to gain game time and experience.

On 13 April 2010, Melbourne announced that they had rejected a bid for Langerak from German giants, Borussia Dortmund, however talks continued. On 4 May 2010, Langerak revealed to FourFourTwo Magazine, that Borussia Dortmund had made a second, substantially increased, bid for his services on the same day as the interview, but was again rejected by Melbourne Victory.

On 12 May 2010, Melbourne Victory accepted a third offer for Langerak from Borussia Dortmund sealing a four-year-deal with BVB. After joining Dortmund, Langerak became the club’s second choice goalkeeper during the 2010–11 Bundesliga season and was a regular in matchday squads. Langerak said his goal for the season was to learn as much as possible.

Langerak was selected in the Young Socceroos squad to play in the AFC Youth Championship 2006. Langerak received his first senior national team call-up in March 2011, named by coach Holger Osieck as a member of the 17-man squad to play Germany in a friendly match.

On 12 May 2012, two years to the day after sealing his move to Borussia Dortmund, Langerak came on as a 32nd-minute substitute in the DFB-Pokal final against Bayern Munich. He came on for the injured Roman Weidenfeller who had suspected rib damage after a challenge with Mario Gómez earlier in the game. Dortmund went on to win the game 5–2 to claim the cup and Langerak’s third title in two seasons at the club.

On 27 July 2013, Langerak won the 2013 DFL-Supercup with Dortmund 4–2 against rivals Bayern Munich.

On 18 September 2013, Langerak made his Champions League debut against Napoli after Weidenfeller was sent off. He broke two front teeth in collision with a goalpost in an unsuccessful attempt to stop Lorenzo Insigne scoring.

Langerak made his debut for Australia in an international friendly against France on 12 October 2013, a match in which the Socceroos were thrashed 6–0, courtesy of goals from Franck Ribéry, Olivier Giroud, Yohan Cabaye, Mathieu Debuchy and Karim Benzema. This match turned out to be manager Holger Osieck’s final match in charge of Australia, with his sacking coming shortly after the conclusion of the match. Langerak made his second appearance for Australia against Canada, a match which Australia won 3–0, courtesy of goals from Joshua Kennedy, Dario Vidošić and Mathew Leckie. Langerak was included in the 23 man squad going to Brazil for the 2014 FIFA World Cup. He was also included in Australia’s final list for 2015 AFC Asian Cup, being held in Australia, but he didn’t play any match even Australia’s triumph at the 2015 Asian Cup.

On 23 August 2014, Langerak conceded the fastest goal (9 seconds), in the history of Bundesliga, on the opening game of the season 2014–15, a home match against Bayer Leverkusen, which ended 0–2 loss for Dortmund.

For the 2015–16 season, Langerak moved to VfB Stuttgart. Mitchell Langerak made his Bundesliga debut for VfB Stuttgart on 7 May 2016 at home to FSV Mainz 05. The season ended with Stuttgart’s relegation to the 2. Bundesliga. After the departure of Przemysław Tytoń, Langerak was handed the starting position and instantly became a fan favourite.

On 30 August 2017, Langerak joined Levante on a two-year deal.

On 14 January 2018, Langerak signed for Nagoya Grampus.