Kouzmanoff will make $3.1 million this season and Davis will get a $1.35 million contract plus incentives. The deals were reached before Tuesday's deadline to exchange contract figures.
Right-hander Michael Wuertz is the only A's player remaining eligible for arbitration.
Kouzmanoff was acquired in a trade over the weekend from San Diego. He hit .255 with 18 homers and a career-high 88 RBIs last season with the Padres.
Davis became the starting center fielder in Oakland last season, hitting .305 and stealing 41 bases. He is expected to play left field this season following the signing of Coco Crisp.
Davis can earn an additional $150,000 in performance bonuses: $25,000 each for 435, 450, 500 and 550 plate appearances, and an additional $50,000 for 600 plate appearances.