For the federal electoral district, see Wellington—Halton Hills

Wellington—Halton Hills is a provincial electoral district in western Ontario, Canada. It elects one member to the Legislative Assembly of Ontario.

The riding, which was first contested in the 2007 provincial election, consists of the municipalities of Guelph/Eramosa, Puslinch, Erin, Centre Wellington and Halton Hills.

47.5% of the riding came from Halton, 25.2% came from Waterloo—Wellington, 16.3% came from Guelph—Wellington and 11% came from Dufferin—Peel—Wellington—Grey.

Election results

|- |Ted Arnott |align="right"|21,533 |align="right"|49.2 |align="right"| |- |Marg Bentley |align="right"|13,311 |align="right"|30.4 |align="right"| |- |Martin Lavictoire |align="right"|4,484 |align="right"|10.2 |align="right"| |- |Noel Duignan |align="right"|3,902 |align="right"|8.9 |align="right"| |- |Giuseppe Gori |align="right"|559 |align="right"|1.3 |align="right"| |}

Ontario electoral reform referendum, 2007
Side		Votes	%
	First Past the Post	28316	66%
	Mixed member proportional	14589	34%