The "Man of Steel" actress, 48, filed court documents last Friday in Los Angeles Superior Court and cited "irreconcilable differences" for the split, according to reports.
Lane signed the docs on Valentine's Day.
She is also trying to legally restore her previous name, court documents indicated. When the couple married in 2004, she changed her name to Diane Lane Brolin; however, the Oscar-nominated actress has always gone by Diane Lane professionally. The couple has no children together and there was no indication of a prenuptial agreement.
News of the split surfaced Thursday, with a source saying, "It was a mutual decision. It is very amicable. It's not ugly, it's just over."
Lane listed the legal date of separation as Feb. 13 and she signed the documents on Valentine's Day, according to court records obtained by TMZ. But the couple has reportedly been on the outs for longer. Meanwhile, Brolin, 45, was photographed smiling along with a mystery woman Friday morning, TMZ reported.
A few months after marrying, the "True Grit" actor was arrested on suspicion of spousal battery, but Lane declined to press charges. He was later arrested after a bar fight in 2008.
This is the second divorce for both actors. In 1994, Brolin split from Alice Adair and Lane divorced Christopher Lambert.