Youth career (2008–2010)

Richardson was born in Eudunda in country South Australia, but he spent much of his childhood in Darwin in the Northern Territory. He moved back to South Australia to play for the Southern Redbacks, making his Twenty20 debut in the 2008–09 Big Bash and his one-day debut in the 2008–09 Ford Ranger Cup.

In 2009 Richardson was named in Australia's under-19 squad for their tour of India ahead of the 2010 Under-19 Cricket World Cup. While on tour in India he managed a five-wicket haul in a youth test against India. After the tour he went with the team to Kenya to play in the World Cup. He played three matches in the tournament and impressed with both bat and ball. His first standout performance came against Ireland, when he scored 23 runs from 14 balls and took three wickets with the new ball to help Australia to a crushing 209-run victory. He was brought into the team for the final of the World Cup against Pakistan, top-scoring with 44 runs to help Australia to their third Under-19 World Cup title. During his youth career Richardson played in two youth Test matches and ten youth One Day Internationals (ODI).

Continued career and international debut (2010–2013)

Richardson continued to play for the Redbacks and was a crucial part of their win in the 2010–11 Big Bash, taking three key wickets against New South Wales in the final of the tournament. His form carried over into the other forms of the game in this season as well, with a man-of-the-match bowling performance against Queensland in the Ryobi Cup being followed up with his first-class debut for South Australia in the next Sheffield Shield game. He was impressive on debut, taking a wicket in each of his first three overs of first-class cricket. At the end of the season he was upgraded from a rookie contract with South Australia to a full contract for the first time, and