Sumter County State Court Judge Russ Barnes notified Gov. Nathan Deal on Thursday of his decision to leave the bench.
The Judicial Qualifications Commission said in a court filing Friday that it had been investigating allegations that Barnes misappropriated official funds.
The Atlanta Journal-Constitution reports that the commission did not offer further details.
Barnes signed a consent order promising never to seek or accept judicial office in the future.
Barnes did not return a phone call seeking comment.
He is the seventh Georgia judge to resign or retire this year while being investigated over misconduct allegations.