Patrick Galen Dempsey (born January 13, 1966) is an American actor and race car driver, known for his role as neurosurgeon Dr. Derek Shepherd ("McDreamy") on the medical drama Grey's Anatomy. He has also recently appeared in several films, including Sweet Home Alabama, The Emperor's Club, Freedom Writers, Enchanted and Made of Honor.

Dempsey was born in Lewiston, Maine and grew up in Buckfield, Maine, the youngest of three children born to Amanda and William Dempsey. He has Irish ancestry. Dempsey attended St. Dominic Regional High School for his senior year, where his mother worked as a secretary, but dropped out before he graduated. He was an adept juggler, tying for second in a national juggling competition. He was also an accomplished skier and while in high school won the Maine state slalom championship. Dempsey spent some of his school years in the town of Turner, Maine, where he attended Leavitt Area High School in the Maine School Administrative District (MSAD) #52 for his freshman through junior years.

Dempsey was diagnosed with dyslexia at age twelve. He told Barbara Walters on her 2008 Oscar's special that he thinks dyslexia "made him what he is today." “It’s given me a perspective of — you have to keep working,” Dempsey tells Walters. “I have never given up.”