In 71 appearances last season -- Britton's first as a reliever -- the left-hander posted a 1.65 ERA with a 0.90 WHIP. He recorded 37 saves in 41 chances.
Britton has spent four seasons in the Majors, all with Baltimore. He struggled as a starter from 2011-13 but was extremely effective in his first stint as closer.
With the Britton deal in place, outfielder Alejandro De Aza is now the Orioles' only remaining arbitration-eligible player who has not yet signed a deal.
AJ Cassavell is a reporter for MLB.com. Follow him on Twitter @ajcassavell. This story was not subject to the approval of Major League Baseball or its clubs.