The Reds also agreed to a one-year contract with Fred Lewis, a left-handed hitter who can play all three outfield positions and bat leadoff.
The 35-year-old Renteria became a free agent after the Giants declined his $9.5 million contract option. His tiebreaking three-run homer off Cliff Lee helped the Giants win the World Series. He was hurt most of the season, spending three stints on the disabled list.
Lewis batted .262 with Toronto last season, leading the club with 17 steals. His 31 doubles were third-most by an AL leadoff hitter.
The Reds announced the deals on Monday.