The actress and singer, now 36, exchanged vows with rocker Ryan Adams in 2009 during a difficult time personally, and tells the November issue of Glamour magazine she wishes she hadn't dived into marriage.
At the time, Moore's world was rocked by the news her mother was leaving her dad for another woman.
"I couldn't control what happened to my immediate family, but I could control starting my own," she says. "(It was) not the smartest decision. I didn't choose the right person."
Mandy admits she found herself "spiritually and fundamentally stuck" in the marriage, which ended when she and Adams separated in 2015. She and Ryan divorced the following year and now Moore is engaged to another singer/songwriter, Taylor Goldsmith.
"I don't feel guilty for it, I don't fault myself for it," she says of the divorce. "When people said, 'I'm sorry', I was like, 'Sorry would have been had I stayed in a very unhealthy situation'. I didn't. I found my way out. And when I did, things opened back up again."
"I'm a woman now. I've been married and divorced. I've had ups and downs, professionally and personally," she adds.
Mandy was still "dealing with the trauma" of her divorce when she met Goldsmith, revealing he was a rock for her when she needed a good man in her life: "Taylor was steadfast in his support (and) that was a huge sign for me."
And now she's convinced she won't be making another marriage mistake when she weds for a second time, telling the publication, "I can imagine no better partner... I would gladly weather all of that a million times over if it brought me to Taylor again."