William Lahey (born May 30, 1961 in Miramichi, New Brunswick) is a Canadian lawyer, public servant, and the 25th president and vice-chancellor of the University of King's College in Halifax, Nova Scotia.

Lahey began his career as clerk for Mr. Justice La Forest of the Supreme Court of Canada and later practiced with the Halifax firm of McInnes, Cooper & Robertson.

From 2004 to 2007 he was deputy minister of Nova Scotia’s Department of Environment and Labour, on leave from Dalhousie Law School.

[3] In August 2018, Lahey published An Independent Review of Forest Practices in Nova Scotia which proposes a shift toward a so-called "new paradigm of 'ecological forestry'".

During the 2021 Liberal leadership race Iain Rankin pledged to implement the Lahey Report in its entirety by the end of 2021,[5] this was cut short however by a Progressive Conservative upset victory in the 2021 Nova Scotia general election.