The Indians also claimed backup infielder Chris Gomez on waivers from Baltimore.
Branyan joins his sixth team since making his major-league debut with the Indians in 1998. The 31-year-old left-handed hitter began this season with San Diego and hit .197 with seven homers and 19 RBIs in 61 games. He was released on July 28, signed with Cleveland on Monday and played one game at Triple-A Buffalo.
The Phillies will announce a move before their game against Florida to make room for Branyan.
In parts of 10 seasons in the majors, Branyan has a career average of .229 with 118 homers and 293 RBIs in 688 games. He's also played for Cincinnati, Milwaukee and Tampa Bay.
Branyan's versatility should help the injury-depleted Phillies. He's played third base, first base and both corner outfield spots.
All-Star second baseman Chase Utley and outfielders Shane Victorino and Michael Bourn are among several players on the disabled list for Philadelphia, which entered the day four games behind the NL East-leading Mets and one back in the wild-card race.
Branyan twice hit more than 20 homers. He had 20 for Cleveland in 2001 and combined for 24 with the Indians and Reds in '02.
Gomez hit .302 with one homer and 16 RBIs in 169 at-bats for the Orioles. He played all four infield positions and was eager to join the AL Central-leading Indians.
"I've heard lots of good things about the Cleveland organization, so it's something to look forward to. But of course I'm going to miss the guys here," he said.