Blair Montgomery Thornton (born July 23, 1950) is a Canadian guitarist and songwriter most widely known for his work with the rock band Bachman-Turner Overdrive (BTO).

In interviews years later, Randy noted that Blair Thornton was a welcome addition: He was known for playing in the Eric Clapton/Bluesbreakers style.

[4]As a songwriter, Thornton contributed two compositions to the Not Fragile album: "Givin' It All Away" and an instrumental called "Freewheelin'" that also wound up as the B-side of the No.

Following Randy Bachman's departure from the group in 1977, Thornton took over as primary lead guitarist on their next two albums: Street Action (1978) and Rock n' Roll Nights (1979), also contributing several compositions.

In 2014, Thornton along with original band members Fred Turner, Robbie and Randy Bachman were inducted into the Canadian Music Hall of Fame.