Prince, 47, shares the honor with Kristen Bell, the 25-year-old star of Veronica Mars, which is being carried over from UPN to the new CW Network this fall.
A strict vegan, Prince recently wrote in the liner notes of his latest album, 3121, about the ills behind wool production. He closed the disc with a quote from Mahatma Gandhi: "To my mind, the life of a lamb is no less precious than that of a human being."
Bell, in a statement, said of her vegetarianism: "I had a hard time disassociating the animals I cuddled with — dogs and cats, for example — from the animals on my plate, and I never really cared for the taste of meat. I always loved my brussels sprouts!"
Runners-up in the poll, which PETA said received over 40,000 votes, include Natalie Portman, Nicollette Sheridan and Joaquin Phoenix.
Last year, Coldplay singer Chris Martin and American Idol Carrie Underwood were picked as the two "sexiest vegetarians." Other previous winners include Andre 3000, Tobey Maguire, Josh Hartnett, Alicia Silverstone, Lauren Bush and Shania Twain.