He's expected to continue to work with the company as a consultant, but more details about what he'll do next weren't forthcoming.
Lockhart served as President Bill Clinton's spokesman and was a founding member of the Glover Park Group. Here's AllThingsD's Mike Isaac with more details:
His departure comes nearly 15 months after he first joined the company in July of last year, where he worked alongside of Marne Levine, another beltway insider who has served Facebook as VP of global public policy since 2010.
The decision comes in part because of Lockhart's desire not to move to California full-time and stay on the east coast, where he has continued to reside throughout his employment at Facebook, a source familiar with the matter says.
The post, originally published at 8:35 a.m., has been updated.