'One Tree Hill' Actor Paul Teal Died After Battle With Pancreatic Cancer

Paul Teal, famous for his work on "One Tree Hill," died 7 months after being diagnosed with stage 4 cancer ... TMZ has learned.

The actor's fiancée, Emilia Torello, tells TMZ ... Paul was diagnosed back in April with stage 4 neuroendocrine pancreatic cancer.

Paul died Friday in a hospital in Raleigh, NC, and Emilia tells us ... "He was the most talented man I’ve ever met. When he set his mind to something, there was no stopping him. He was the most diligent and dedicated person. I truly believed with all of my heart that he would come out the other side of this because of those traits. That’s what makes this loss even more tragic."

During his cancer battle, Emilia says Paul filmed a brand new series for Starz, "The Hunting Wives," and she says he felt being around the cast and crew helped him keep the fight going.

Meanwhile, Paul's former "One Tree Hill" costar Bethany Joy Lenz says she's "gutted" by his death.

Bethany says she worked closely with Paul on a musical production of "The Notebook" ... remembering him as "the kind of guy who could light up a room without trying." She also says he was a joy to work with and was generous.

Paul was only 35.