The actor has been tapped to star in "Disenchanted", and the flick will mark the star's first public singing gig of his entire career, he has confirmed.
"I will be singing for the first time. I've never ever sung publicly - for a reason," he told Variety. "So bear with me."
But Patrick hopes "fans embrace it," adding, "But they've set me up for success and the lyrics are really fun. The numbers have really great choreography. And the premise is going to be interesting."
"I don't sing with her," he stated before teasing there are "a lot of cool numbers in this."
During the interview, Patrick Dempsey also talked about his "Grey's Anatomy" return, calling it a "beautiful way" to leave the show.
The actor - who played Derek 'McDreamy' Shepherd in the hit TV series - recently made a surprise return to the show, when Dr. Meredith Grey dreamed of herself and Derek finally having their wedding on a beach, but Patrick has suggested he won't be making another comeback.
He shared, "I thought it was a beautiful way to close it. The intention was to really give people some hope because they are such an iconic couple."
"We've lost so many people this year, the thought that we'd have angels hovering around us taking care of us is a good message to send out in such a bleak world that we're living in. So for all of us, it was a beautiful ending to this story."
"I'm so grateful that I did it and happy that the fans really loved it."
Patrick and Ellen Pompeo - who plays Meredith - used his comeback to highlight the importance of wearing a mask amid the coronavirus pandemic.
And the actor admitted that shooting his final scenes was an emotional experience, telling Variety, "We all cried at the beginning and we hugged each other."
"It was really for us to get the message out there to wear a mask, take care of yourself. Ellen and I were like, 'What can we do together to make some impact here?' "
"That was in the spring around this time last year. It just was a positive action that reverberates into more positive action."
Asked if there's another scenario in which he could make a comeback, Patrick replied, "Who knows? Never say never with this show, right?"
"I'm glad we did it this year. And Krista Vernoff did a fantastic job telling the story. It was just a great way to give people some hope."