Jessica Brook Rentchler lives with her father Alvin in Crawfordsville. He reported her missing at about 8 p.m. on June 30, the Montgomery County Sheriff's Department said.
She was last seen at their residence, 1979 E. CR 300S, Crawfordsville.
Authorities believe she is likely a runaway, although there is no indication the teenager had ever previously run away from home.
A white female, Jessica Rentchler is 5 feet, 10 inches tall and weighs about 120 pounds. She has blue eyes and long dark blond hair.
Anyone who has any information on her whereabouts is asked to call the Montgomery County Sheriff's Department at 362-3740.