The Yankees made the announcement at Yankee Stadium during Sunday's game against the Seattle Mariners, The New York Times reported. Yankees' public address announcer Bob Sheppard asked fans to turn their attention to the owner's box behind home plate, where they saw Clemens.
"It's a privilege to be back," he said. "I'll be talking to you soon."
Clemens, 44, signed a minor league contract, the Yankees said in a release. Details were not immediately available.
Yankees' principal owner George Steinbrenner issued a statement calling Clemens a "winner and a champion."
"As I pledged just a few years ago, I will do everything within my power to support (General Manager) Brian Cashman, (Manager) Joe Torre and this team as we fight to bring a 27th championship back to New York," Steinbrenner said.
Clemens pitched for the Yankees from 1999 to 2003. His career record with the Yankees, the Boston Red Sox, the Toronto Blue Jays and the Houston Astros is 348-173, with a 3.10 ERA and 4,604 strikeouts.