Ferrell has been tapped to replace the fired Bobby Valentine following Boston's disastrous, last-place 2012 campaign, in which the Red Sox compiled their worst record (69-93) since 1965.
The move came after multiple media reports indicated Farrell -- who has managed the Blue Jays since 2010 -- had been signed to a two-year contract.
The 50-year-old compiled a 154-170 record in his two years with the Blue Jays. He is under contract with Toronto until 2013, so the Red Sox have agreed to send veteran infielder Mike Aviles to Toronto as compensation, WEEI-AM, Boston, said.
The reports indicated Farrell will be introduced at Fenway Park Monday or Tuesday.
Valentine was fired after one season with the Red Sox.