A Multnomah County judge finalized the divorce Tuesday, the (Portland) Oregonian reported Wednesday.
The couple were married in 2007. Kaine Horman filed for divorce in 2010, 24 days after his 7-year-old son Kyron was last seen at his Portland elementary school.
The boy's disappearance led to the state's largest search-and-rescue operation but turned up no trace of him. A criminal investigation continues, but no arrests have been made.
Kaine Horman has said publicly he suspects Terri Horman was involved in Kyron's disappearance, but she has not been charged or pinpointed as a person of interest, the Oregonian said.