William Haskell is an American politician and a former member of the Connecticut State Senate, representing District 26 from 2019 to 2023. The district includes the towns of Redding, Ridgefield, Wilton, and parts of Bethel, Weston, Westport, and New Canaan. The 26th District has not been represented by another Democrat since 1973. Haskell is a member of the Democratic Party, and was a member of the State Senate Democratic Caucus.

Connecticut's 26th State Senate district elects one member of the Connecticut State Senate. The district consists of the entirety of Westport, Wilton, Ridgefield, and Redding, and parts of Bethel, New Canaan and Weston. Previously, the 26th district comprised Norwalk, Wilton, New Canaan, and Easton. However, in the late 1970s Norwalk and Darien became the 25th district. It is currently represented by Democrat Ceci Maher since 2023.