Happy Birthday Hugh Hefner! Which Sexy TV Stars Have Posed in Playboy?!

The "Dancing with the Stars" pro will go nude for Playboy's May 2011 edition.

Along with Pamela Anderson and Carmen Electra, Traci Bingham and Gina Lee Nolin appeared in Playboy's Babes of "Baywatch" issue in June 1998.

Late model-turned-reality star Anna Nicole Smith was Playboy's 1993 Playmate of the Year.

Adrianne Curry used her "Top Model" talents when she revealed her fine form in the mag's January 2008 issue.

"Star Trek: Enterprise"'s Jolene Blalock was an intergalactic goddess when she beamed down to do the April 2002 issue.

Reality queen Kim Kardashian highlighted her famous assets and bared it all in the December 2007 issue.

Pictured here just months after her 12-page, 1983 Playboy shoot, "Dynasty"'s British diva, Joan Collins proved that at 49 years old, she was still the talk of the town.

"Dancing with the Stars" dynamo Brooke Burke got wild and showed off her rockin' bod in May 2001 and November 2004.

Taking it all off for this month's Playboy, 45-year-old Lisa Rinna also stripped down for the September 1998 issue.

Former Miss USA and reality gal Shanna Moakler showed her moves off when she was named Miss December in 2001.

"Battlestar Galactica" hottie Tricia Helfer looked out of this world when she went topless in February 2007.

"Buffy the Vampire Slayer" and "Angel" star Charisma Carpenter slayed the pages of Playboy in a 10-page, semi-nude layout in the June 2004 issue.

The "Three's Company" beauty was 37 years old when she dropped her top for the December 1984 issue of the magazine.

No stranger to posing for Playboy, "Baywatch" star Carmen Electra electrified eyes in May 1996, June 1997, June 1998, December 2000, April 2003 and January 2009.

"My Name is Earl" star Jaime Pressly brought joy to readers when she showed off her assets in the March 1998 and February 2004 issues.

TV bad girl Shannen Doherty has twice charmed the covers of Playboy -- first in March 1994 and again in December 2003.

"Dancing with the Stars" contestant Joanna Krupa was on the cover of the December issue of Playboy. The dancing diva bared it all in an 8-page nude pictorial spread.

Heidi Montag got down and dirty in the Sept. 2009 issue of Playboy.

Outrageous talk-show host Chelsea Handler kept her clothes on for Playboy's December 2009 issue. The late-night host shared her December cover-girl honor with "Dancing with the Stars"' Joanna Krupa. Handler's cover was only available on stands, while Krupa's cover went out to subscribers and was also available on newsstands.

Jenny McCarthy was singled out by Playboy when the mag named her Miss October 1993. The funny girl went on to become Playmate of the Year in 1994.

"Baywatch" babe Pamela Anderson began her playmate career back in 1989. Since then, the platinum blonde has appeared on Playboy's cover a record 14 times, most recently in January 2011.

Happy 85th Birthday Hef! As a tribute to Hugh Hefner, the man who loves the ladies, ETonline has some of TV's biggest hotties who have taken it all off for Playboy. What do "Dancing with the Stars" babe Karina Smirnoff, wild talk-show host Chelsea Handler and controversial reality star Heidi Montag have in common? All of their hot bods have graced the covers of the mag!

So, which other of TV's sexiest stars have dared to bare on the pages of Playboy? Keep clicking to find out!