Reynolds, 34, starred in the blockbusters "The Proposal" and "X-Men Origins: Wolverine." The husband of actress Scarlett Johansson also will soon be seen playing the superhero the Green Lantern on the big screen.
"My body naturally wants to look like Dick Van Dyke," the actor told People. "When I stop training, I turn into a skin-colored whisper."
Reynolds told the magazine he doesn't plan to let his new title go to his head.
"You just have to go with the flow," he said. "This gives my family entre into teasing me for the rest of my life."
He also said he doesn't expect the honor to affect his relationship with his wife too much.
"Now it's going to be, 'Sexiest man, take out the garbage.' That does sound better," Reynolds said. "The most difficult part is going to be organically working this title into a conversation with random strangers."