The actor died "surrounded by his family in California... after a courageous battle with cancer," according to a statement by television network ABC. He filmed his last episode of "General Hospital" on August 24.
"With great sadness, I share the news of John Ingle's passing. We love him and will miss him. John will always be a part of the #GH family," the show's executive producer Frank Valentini tweeted on Monday.
Ingle was born in Tulsa, Oklahoma, in 1928, and his family moved throughout the Midwest before settling in California when Ingle was a teenager.
He attended Occidental College in Los Angeles and went on to teach drama at Beverly Hills High School and Hollywood High School for a combined 30 years. His students included Richard Dreyfuss, Barbara Hershey, David Schwimmer and Nicolas Cage.
Ingle pursued an acting career after retiring from teaching in 1985. In addition to his longstanding role on "General Hospital", Ingle's television credits include "Cheers," "The Drew Carey Show," "Beverly Hills 90210" and "Dallas."
Ingle married actress and singer Grace-Lynne Martin in 1954 , and they were married for 57 years until her death earlier this year from natural causes. Together they had five daughters and nine grandchildren.