Amy Poehler and Will Arnett divorced primarily because their marriage "fizzled out" and the romance "died," leading them to feel more like best friends than romantic partners. They both acknowledged that they grew apart and were no longer happy in the marriage, prompting their decision to separate. The split was described as amicable with no malice or infidelity involved. Will Arnett did relapse into alcohol use around the time of their separation in 2012, but neither he nor Amy has indicated that this relapse or substance use played a direct role in their divorce. Amy Poehler has also expressed that she prefers to keep the details private, describing the experience as painful but emphasizing that their nearly 10-year marriage was not a failure, and highlighting their continued co-parenting relationship and mutual respect despite the divorce. They filed for divorce in 2014 and finalized it in 2016 after separating in 2012. In short, the divorce was due to growing apart and the end of the romantic aspect of their relationship rather than scandal or external drama.
