The couple's rep confirmed to TheInsider.com that they are separating. A source tells Us Weekly, "It's very amicable."
Arnett and Poehler wed in 2003 and have two sons: Archie, 3, and Abel 2.
The two have played opposite each other in such projects as Arrested Development, Blades of Glory, Horton Hears a Who! and Monsters vs. Aliens.
This marks Arnett's second marriage breakup, as he divorced Penelope Ann Miller in 1995 after being wed for one year.
Hot New Hookups! | The Latest Hollywood Trends | Summer’s Hottest New Movie
- Will Arnett
- Amy Poehler
- Penelope Ann Miller