He represented the electoral district of Colchester in the Nova Scotia House of Assembly between 1945 and 1949.
[3] He ran again in 1945, and was elected in the dual-member Colchester riding with Liberal Gordon Purdy.
[4] In the 1949 election, McLellan was defeated by Progressive Conservative leader Robert Stanfield and George Isaac Smith.
[5] McLellan ran as a Liberal candidate in the 1958 federal election, but was defeated by Progressive Conservative Cyril Kennedy in Colchester—Hants.
[6] On January 5, 1966, McLellan was appointed a County Court judge, and served in the position until September 30, 1981.