The midfield general has been out with a broken collarbone since sustaining the injury against Napoli in November.
The return of their vice-captain comes as a boost for Bayern who are hoping to challenge Borussia Dortmund for the Bundesliga this year.
"It's been a difficult period," Schweinsteiger told the club's website.
"The timing was right. I'd rather be injured prior to the winter break than in April when trophies are at stake.
"I'm feeling very good, I'm a little uneasy with certain movements. I'm setting the bar very high for the new year. I expect a lot of myself."
The 27-year-old has been at Bayern Munich his entire career, joining in 1998.