The attack happened just after 9:30 a.m. Monday in a gated community on Hilton Head Island, South Carolina.
According to the Beaufort County Sheriff's Office, witnesses saw the woman being attacked by an alligator as she walked her dog near a golf course. She has been identified as Cassandra Cline, age 45.
Emergency crews recovered Cline's body from the lagoon. Her dog was not harmed during the incident.
Authorities caught the alligator they believed to be responsible for the attack, and disposed of it.