The Grammy-nominated comedienne, 47, shared the news on Twitter on Monday.
"The great @michaelsheen & I consciously uncoupled over Christmas," she tweeted.
"I mean, not 'over Christmas' - like that wasn't the fight that ended it. No fight. We just live in different countries & it got hard. Felt we should just tell y'all so u stop askin, 'How's Michael/How's Sarah?" she said in another tweet.
Page Six reported that they starting dating in January 2014. They also starred alongside one another for two seasons of the Showtime drama "Masters of Sex." (ANI)