The Big Blue Machine was a nickname for the group of strategists and advisors to the Ontario Progressive Conservative Party in the 1970s and 1980s. The moniker was coined by journalist Claire Hoy of the Toronto Star in April 1971. It has most frequently been applied to Bill Davis' term in office from 1971 to 1985 where his Red Tory government won election after election by promising moderate well run government. Davis' period was only a portion of an unprecedented 42 years of straight Tory rule in Ontario, and sometimes earlier organizations are also referred to by the Big Blue Machine moniker.

Noted members included Alan Eagleson, William Kelly , Patrick Kinsella , Gerald Nori , Eddie Goodman , and Ross DeGeer . The party workers were often accused of being dismissive of the MPP's they got elected, and would sometimes draft legislation without any input from the Tory caucus or cabinet.

The Big Blue Machine was finally defeated in 1987 and while the Tories returned to power in 1995, the era of centrist governance, where the Tories often ran to the left of the Liberals, was over.