Thomas McCullouch Fairbairn (April 19, 1840 – May 13, 1874) was a Canadian lawyer and politician.

He represented Peterborough West in the Legislative Assembly of Ontario from 1871 to 1874.

Fairbairn was born in Bowmanville in 1840, the son of a Scottish immigrant.

He was elected to the Ontario legislature in 1871 for the Reform Party and died in Jacksonville, Florida while still in office, likely of consumption.

[1] His son, John Morrice Roger Fairbairn, became chief engineer for the Canadian Pacific Railway.