At domestic level he played for Cape Cobras, Warriors and Eastern Province in South Africa and for a range of teams in competitions around the world.

Parnell made his first-class cricket debut for Eastern Province in October 2006, at the age of seventeen, against South Western Districts scoring 17 and taking one wicket.

[7] At the start of the 2009 season Parnell was signed as an overseas player by Kent County Cricket Club on a six-week contract, serving as a replacement for Stuart Clark.

[13][14] In 2015 he played for Glamorgan in eight matches in the 2015 NatWest t20 Blast group stages before joining South Africa on their tour of Bangladesh.

He was available for the first weeks of the 2017 County Championship and 2017 Royal London One-Day Cup matches until South Africa began their tour of England in May.

[22] Parnell was bought the Delhi Daredevils in auction for the 2010 Indian Premier League (IPL), after they outbid the Deccan Chargers for his services.

[26] Whilst a Pune player he was one of 90 people detained by police after a rave party he was attending in a Mumbai suburb was raided in 2012.

In June 2018, he was selected to play for Edmonton Royals in the players' draft for the inaugural edition of the Global T20 Canada tournament.

He was expensive with the ball and put down a crucial catch, but it was later suggested that this was the result of a green laser light beamed into his eyes by a member of the crowd.

Sharing the new ball with Dale Steyn, he played a key role in South Africa's seven-wicket win in the second ODI at Centurion by taking four for 25.

Parnell confirmed that his teammates Hashim Amla and Imran Tahir, along with team manager Mohammad Moosajee, had no influence over his decision.