However, take heart: They remain "very, very good friends," Poehler said.
"I don't think a 10-year marriage constitutes a failure," the actress told Howard Stern during an interview for his Sirius XM radio show. "I think relationships are really tough."
Poehler, 43, and Arnett, 44, were married in 2003 and had two children, Archie, 6, and Abel, 4.
Entering into the dating scene for the first time in years was tough for the actress, who said that she had to learn how to text with potential new boyfriends, among other things.
"I remember I was at dinner with John Stamos ... and I was like, 'Oh, maybe this is a date!' ... but I blew it," she recalled with a laugh. "I remember thinking, like, 'Oh s***, if this is really a date, I think I was wearing a Leslie Knope shirt -- I think a shirt from [the set of "Parks and Recreation."] I wasn't foxy."
Now, she's happily dating comedian Nick Kroll, with whom she said she'd been friendly for years prior. Arnett, she said, has also met him.
"They know each other!" she said. "It's all fine."