Mitchell Ross Marsh (মিচেল রস মার্শ) is an Australian international cricketer who represents Australia in all three formats. Marsh is the current Australian T20I captain, and has served as vice captain in all formats. Marsh currently plays for Western Australia, at for domestic cricket, and Perth Scorchers in the Big Bash League.

Marsh is the second son of Geoff Marsh and younger brother of Shaun Marsh, both of whom have played for the Australian national side. His sister, Melissa Marsh, is a former professional basketball player and he is cousin to retired AFL player, Brad Sheppard. He was raised in Perth, Western Australia, where he attended Wesley College.

In addition to cricket, Marsh was also a talented Australian rules footballer in his youth and represented Western Australia at the 2008 AFL Under 18 Championships. Although a West Australian, Marsh has stated that he has always supported the North Melbourne Football Club.

Marsh made his debut for the Warriors at the age of 17 in February 2009 in a Ford Ranger Cup game at Bunbury. He became the youngest ever player in an Australian domestic one-day game and Western Australia's youngest debutant for 70 years. In April 2009, he played for Australia's under-19 team against India and was the team captain during the 2010 Under-19 Cricket World Cup. Under his leadership Australia won the tournament, Marsh having a successful tournament scoring 201 runs, including a match winning 97 in the semi-final against Sri Lanka.

In September 2011, Marsh was named in Australia's Twenty20 squad to tour South Africa. He was later added to the One Day International squad following Brett Lee's withdrawal due to injury. He made a spectacular debut for Australia in the second T20I match of the series, scoring 36 runs including four sixes, three of which were hit in the final over of the Australian innings. In August 2014, Marsh scored 89 runs against Zimbabwe in first match of the Tri-series at Harare Sports Club, adding 109 runs for the fourth wicket with Glenn Maxwell and contributing to partnerships of 47 and 33 with Aaron Finch and George Bailey. Later in the competition he scored 86 not out against South Africa.

Playing regularly in the One Day International side, Marsh took a five-wicket haul against England during the 2015 Cricket World Cup and scored his maiden ODI century against India in 2016 at the SCG. He was, however, dropped from the Australian Test side after the first Test of the 2016–17 series against South Africa, coming back into the side during the 2017 series against India and playing in two Tests before he suffered an injury. Later in the year, he replaced Peter Handscomb in the third match of 2017–18 Ashes series, scoring his maiden Test century. His first innings score of 181 was one short of his brother Shaun's career best score of 182.