William "Bill" Lafferty (1931–2003) was a politician, Canadian Forces officer and newspaper columnist from Northwest Territories, Canada. He served as a member of the Northwest Territories Legislature from 1975 until 1979.
Lafferty was first elected to the Northwest Territories Legislature in the 1975 Northwest Territories general election. He won the Mackenzie-Laird electoral district defeating incumbent Nick Sibbeston. Lafferty would only serve a single term in office and would not return when the legislature was dissolved in 1979.
He died in 2003 due to cancer.