William Smithe (June 30, 1842-March 28, 1887) was a British Columbia politician. Smithe was born in England but moved to Canada in his youth and settled on Vancouver Island in 1862 as a farmer. In 1871 he ran in BC's first election and won a seat in the new provincial legislature. By 1875 he became the informal leader of the opposition to Premier George Anthony Walkem's government but yielded the leadership to Andrew Charles Elliott. Smithe was in Elliott's short lived cabinet from 1876 to 1878 before returning to the opposition benches and again became opposition leader.

In 1883, Smithe became premier of the province and initiated the Great Potlatch era in which governments made generous grants of public resources and land to private entrepreneurs. He also settled disputes with the federal government which had stalled the construction of the trans-continental Canadian Pacific Railway. He remained premier until he died in office in 1887.