Starc started playing cricket from a young age, at 9 years old for Northern District as a wicketkeeper. He is also a former junior cricketer for the Berala Sports Cricket Club in Sydney, Australia, who attended Homebush Boys High School also representing the school's 1st grade cricket team. He was known to wicketkeeper and bowl in the same innings during his time with the club. Mitchell Starc was also a representative cricketer of the Northern District Cricket Association (NDCA).

Starc debuted for his home state New South Wales in 2009, at the age of 19. His performances for Western Suburbs and the state 2nd XI earned him the elevation and he replaced the suspended Aaron Bird for the final match of the season. Starc, gained a spot at the Centre of Excellence in the off-season in 2009. In eight Sheffield Shield games in the 2009–10 season he took 21 wickets, including a best of 5 for 74 against Queensland, and also made a half-century.

In 2015, Starc maintained his dominance at the international level by breaking records in the Australian domestic one-day tournament, which came about due to postponement of Australia's tour of Bangladesh. The pure numbers from Starc's tournament underline his dominance: 26 wickets from six matches at an average of 8.12 and a strike rate of 12.3. Starc was named as Player of the Tournament in the tournament in which New South Wales won.

After a series of injuries to several senior Australian fast bowlers, Starc