William George Ballinger (born December 17, 1945 in Toronto, Ontario) is a politician in Ontario, Canada. He served as a Liberal member of the Legislative Assembly of Ontario from 1987 to 1990.

Ballinger was educated at the University of Waterloo and Toronto Teacher's College , and worked as an independent businessman prior to his entry into politics. He served as mayor, councillor and regional councillor in Uxbridge, Ontario.

He was elected to the Ontario legislature in the 1987 provincial election, defeating Progressive Conservative incumbent Ross Stevenson by 482 votes. He served as parliamentary assistant to the Minister of Municipal Affairs from 1988 to 1989.

The Liberals were unexpectedly defeated by the Ontario New Democratic Party in the 1990 provincial election, and Ballinger lost his seat to NDP candidate Larry O'Connor by 1,230 votes. He has not sought a return to the legislature since this time.