William Archibald Rae (May 3, 1875 – May 5, 1943) was a businessman and provincial level politician from Alberta, Canada. He was born in Thedford, Ontario.
Rae was instrumental in the founding of Grande Prairie, Alberta with his work as secretary-treasure in the The Argonaut Company Ltd. The company bought and subdivided land that would become the city. He founded the company with his business partner Alphaeus Patterson.
Rae ran for a seat in the Alberta Legislature for the first time in the 1913 Alberta general election. He was defeated by his former business partner Alphaeus Patterson in a closely contested 3 way race. Patterson would retire at the end of his term and Rae would run for the second time in the 1917 Alberta general election this time winning the Peace River district by a large margin. He would serve 1 term in office before being defeated by Donald Kennedy a candidate from the United Farmers of Alberta in the 1921 Alberta general election.
Rae and Kennedy would end up facing each other as candidates in the 1925 Canadian federal election in the federal Peace River district. He would be defeated in a very close 3 way contest finishing just 42 votes behind Kennedy.