After a brief illness, the celebrity died quietly on Wednesday morning, according to her management.
In the 1960s, Welch rose to fame as an international sex icon thanks to her role as a bikini-clad cavewoman in the 1966 movie One Million Years B.C.
The divorced mother-of-two worked as a cocktail server and a model for Neiman Marcus during a brief stay in Dallas, Texas.
Her major break came in 1964, not long after she returned to Hollywood, when she appeared in the Elvis Presley musicals Roustabout and A House Is Not A Home.
Two years later, she gained notoriety for her appearances in the sci-fi picture Fantastic Voyage and the fantasy film One Million Years B.C.
Although Welch only had a few lines in the latter, advertising photos of her in a revealing two-piece deerskin bikini elevated her to the status of a top pin-up of the time.
Despite her outward appearance, she has often voiced discomfort with how her body is portrayed, once stating that it is neither in her or her nature to be a sex symbol.
The most adorable, gorgeous, and fortunate misconception is undoubtedly that I became one, she said.
She acted as Frank Sinatra's on-screen love interest in 1968's Lady in Cement, as the title transgender heroine in 1970's Myra Breckenridge, and in the 1987 TV drama Right to Die, for which she was nominated for a Golden Globe.
Later in life, she also unveiled a jewelry and skincare line, a Mac Cosmetics beauty line, and her own line of custom-made wigs.
Reese Witherspoon, an actress, was one of those paying tribute, tweeting that she "loved" collaborating with Raquel Welch on Legally Blonde.
Witherspoon praised her for being "elegant, professional, and beyond belief stunning." Simply breathtaking
Viola Davis, an actress and producer, uploaded a video of herself and Cher performing "I'm a Woman" in 1975 and said, "You were timeless to me...iconic."
She sang the same song in 1978 with the well-known puppet Miss Piggy, for which she received an homage on Wednesday from the popular comedy show.
The Disney series tweeted, "We'll never forget our great friend Raquel Welch, one of our favorite guests on The Muppet Show.
On the TV show Sabrina the Teenage Witch, actor Paul Feig claimed he enjoyed working with her.
He wrote: "We've lost a great legend. Kind, hilarious, and a true superstar whom I was pretty much in love with for most of my youth."
She is survived by her daughter Latanne "Tahnee" Welch, who is also an actress, and son Damon Welch.