Davis won a $5 million salary during a hearing last February, when the club offered $4.65 million. The agreement announced Wednesday avoided another hearing next month, and Davis' deal is fully guaranteed.
Davis is Oakland's slugging centerpiece. He hit a career-best 43 home runs, connecting on the season's final day to surpass the season high he set the previous year for Oakland. The 30-year-old is the only A's player aside from Jimmie Foxx (1932-34) with consecutive 40-homer seasons.
Davis' 85 homers the past two seasons are second in the majors to Giancarlo Stanton's 86.
Davis batted .247 with a career-high 110 RBIs in 153 games last season.