During the 2007 season, Timlin appeared in 50 games with a record of 2–1, one save, and a 3.42 ERA. He also made eight appearances with the Triple-A Pawtucket Red Sox while rehabilitating. He made his 1,000th career appearance on August 31, against the Baltimore Orioles. In the postseason, he made three appearances in the ALCS against the Cleveland Indians, and three appearances in the World Series against the Colorado Rockies. In those six games, he pitched innings, facing 30 batters while striking out seven, issuing no walks, and giving up two runs. With Boston's sweep of Colorado in the World Series, Timlin earned the fourth championship of his career. He is the only pitcher to appear in, and win, four World Series without winning at least one with the New York Yankees. On December 7, 2007, Timlin was re-signed to another one-year deal.