The 72-year-old judge added that his time on the bench had been rewarding and he looked forward to spending more time with his five grandchildren.
The judge has repeatedly apologized for his remarks in the Rambold case. He also made an unsuccessful attempt to re-sentence the former teacher after prosecutors said the short prison term given to Rambold violated state law.
The rape victim's mother, Auliea Hanlon, said Tuesday that she was focused on a pending appeal of Rambold's sentence before the Montana Supreme Court, and that Baugh's fate was not a major concern. But Hanlon said she "felt a little bad" for the judge.
"He had 30 years of service and nobody's going to remember him but for this one incident," she said.
Baugh, the son of former Washington Redskins quarterback "Slingin' Sammy" Baugh, first disclosed his retirement plans in an interview with Billings television station KTVQ.
Advocates have waged a campaign to have the state Judicial Standards Commission remove him from the bench.
Those efforts will continue after Baugh's retirement announcement, said Marian Bradley, with the Montana chapter of the National Organization for Women.
"We believe that no matter what happens, we have a huge victory with just him not running again," Bradley said.
Hanlon's daughter killed herself in 2010 before Rambold went to trial, leading to a deferred prosecution agreement that included sex-offender treatment. Rambold violated the agreement by having unauthorized visits with relatives' children and having a sexual relationship with an adult woman.
Baugh sentenced Rambold to 15 years in prison with all but one month suspended and made the comments about the girl's age after the former teacher violated the agreement, re-opening the case.
Rambold served his time in prison and remains free pending the appeal of his sentence by Montana attorney general's office.
Attorneys for the state contend Rambold should serve at least four years in prison. Rambold has not yet responded to the state's arguments.