Onkaparinga Councillor Simon McMahon is the new Acting Mayor after being elected to the position at Tuesday's Special Council meeting.

He will stay in the position until local government elections are held in November.

The position became vacant after the former Mayor, Erin Thompson, was elected to parliament in the recent state election.

Mr McMahon was previously the Deputy Mayor and has been a South Coast Ward Councillor since 2018.

He nominated for Liberal preselection for the seat of Mawson in the recent state elections but was defeated by Amy Williams.  

Mr McMahon said he was he is honoured to be elected to the position of Acting Mayor.

He congratulated Erin Thompson on winning the seat of Davenport and said he was proud of the achievements they had accomplished together.

Ms Thompson said she was proud to leave Council “in a much better position than I found it”.