Ancaster—Dundas—Flamborough—Aldershot was a provincial electoral district in southwestern Ontario, Canada that elected one Member of the Legislative Assembly of Ontario. It was created in 1999 from Wentworth North, Burlington South and Halton Centre. It was abolished in 2007 into Ancaster—Dundas—Flamborough—Westdale, Burlington, Hamilton Centre, Hamilton Mountain and Niagara West—Glanbrook.
The riding included the municipalities of Ancaster, Dundas and Flamborough plus that part of Burlington south of a line going along King Road to the 403 to the QEW.
This riding has elected the following members of the Legislative Assembly of Ontario: