Admitted to the Bar, Ronaldson practised as a barrister and solicitor in Ballarat before entering politics.

Following his retirement from the House of Representatives at the 2001 election, Ronaldson was a consultant and member of a number of boards including Snowy Hydro Limited.

He was co-chair of the Australian Ex-Prisoners of War Memorial project in Ballarat where he assisted with fundraising.

Following the 2007 election, Ronaldson was appointed Shadow Special Minister of State under Brendan Nelson.

[5][6] His resignation became effective on 28 February 2016,[7] creating a casual vacancy which was filled on 9 March 2016 when James Paterson was appointed by a joint sitting of the Parliament of Victoria.