Savitt, 48, will remain Lockerz' chairman and also will make a personal investment in the company she is leaving behind. Mark Stabingas, Lockerz' chief operating officer, will replace Savitt as the startup's CEO.
The hiring announced Monday is one of the first major pieces in the management team that Mayer is cobbling together to help turn around Yahoo. Mayer, 37, became Yahoo's CEO six weeks ago, ending her 13-year stint as a key executive at Internet search leader Google .
Yahoo, which is based in Sunnyvale, Calif., has been stuck in an extended financial funk that has depressed its stock. Mayer is the fifth CEO in the past five years to attempt a turnaround.
"Yahoo is at an important and unique inflection point in its storied history," Savitt said in a statement.
Before launching Lockerz in 2009, Savitt was a marketing and communications sharpshooter at retailers American Eagle Outfittersand Amazon.com .