In 2008 Walsh competed in the Formula Renault 2.0 West European Cup (WEC) for Hitech Junior.

[1] Walsh only competed in limited races in 2009, including the final two rounds of the Australian Formula Ford Championship.

[2][3] In February 2011 he finished 16th in the 2011 Armor All Bathurst 12 Hour driving a Ryan McLeod run HSV VXR Turbo and then moved into the 2011 Fujitsu V8 Supercar Series with the newly expanded Miles Racing.

Walsh moved to Matt Stone Racing for the 2012 Dunlop Series and immediately achieved regular top-five finishes.

Walsh contested the 2015 V8 Supercars Championship for Erebus Motorsport in a Mercedes-Benz E63 AMG before and including the 2015 ITM 500 Auckland, after which he was dropped in favour of experienced drivers Dean Canto and Alex Davison.