Municipal elections were held in Toronto, Ontario, Canada, on December 5, 1966. The elections were the first in Toronto after its merger with several smaller suburban communities on January 1, 1967. Forest Hill and Swansea were annexed by the City of Toronto, Leaside was merged with the Township of East York to become the Borough of East York. Weston was combined with the Township of York to form the Borough of York. The Village of Long Branch and the towns of Mimico and New Toronto were merged with the Township of Etobicoke to form the Borough of Etobicoke.