The couple met at an extreme sports event in 2001 and tied the knot on a beach in Costa Rica in January 2006.
However, they were rumoured to be having relationship troubles last September, a month after Hart was accused of cheating while the singer was away on tour.
Pink was reportedly overheard telling friends that she wanted some time away from her husband.
A source told US Weekly: “She told them, ‘We’re just not getting along anymore. We each need our space. We need our distance. It’s not like it was when we first started.’“
Her publicist Michele Schweitzer confirmed: “Pink and Carey Hart have separated. This decision was made by best friends with a huge amount of love and respect for one another.
“While the marriage is over, their friendship has never been stronger.”