Vidale was born in Washington, D.C.. She grew up in a military family with three sisters and moved around frequently. Her family moved to Victoria, Texas when she was 12 years old. She worked as a waitress in Pasadena, Texas before friends encouraged her to be a comedian.
She began her career in 1986 doing amateur stand-up comedy nights in Houston before quickly progressing to comedy clubs in Washington, D.C., New York City, and Los Angeles. She appeared in the cable comedy special "Rodney Dangerfield: Opening Night at Rodney's Place" on HBO in 1989. On the same special were such notables as Tim Allen, Jeff Foxworthy, and Sam Kinison.
She has continued to do standup throughout her career. She went on a national comedy tour called Thea Vidale, Down & Dirty in 1999. In 2007 she tried out for the reality television show Last Comic Standing, making it to the second round. In 2009, Vidale was part of the "Hot Tamales Live! presented by Kiki Melendez" comedy tour, which was filmed for Showtime. On December 12, 2012, she appeared on Standup in Stilettos, a standup comedy show on the TV Guide Network.
She may be best known for her portrayal of "Thea" on the short-lived 1993 sitcom Thea. The show was cancelled after one season in which it was noted to be "ranked near 50 out of approximately 75 shows in the weekly Nielsen ratings" Nevertheless, she was nominated for a People's Choice Award as Favorite Female in a New Series.
She later made numerous guest appearances on sitcoms, including Ellen, The Wayans Bros., The Drew Carey Show, and My Wife and Kids. In 2007 Thea Vidale made a guest appearance on the television series Ugly Betty playing a hairdresser in the episode "Queens for a Day". That same year, she played the part of Helen's grandmother on the Drake & Josh episode "Really Big Shrimp".
She has also had roles in movies such as 1995's Dr. Jekyll and Ms. Hyde, Jerry Springer's Ringmaster in 1998, and the 2006 Master P comedy Repos.
Vidale made her début on World Wrestling Entertainment (WWE) in January 2006. She appeared as the mother to wrestler Shelton Benjamin, who had been going through difficulties in the preceding weeks. Her first appearance was on the January 2 episode of Raw, where she surprised Benjamin by showing up and yelled at him that he wasn't acting the way Benjamins act. Over the next several weeks, "Momma Benjamin", as she came to be known, was involved in several backstage skits resulting in her challenging wrestlers to matches in Shelton's behalf. Unlike in his streak before her arrival, however, Shelton won the majority of these matches.
On the February 6, episode of RAW Momma Benjamin attempted to interfere in Shelton's match with the Big Show, only to have the Big Show turn to her and scream in her face. After he turned back to finish the match (which he won), Momma Benjamin fainted to the ground, prompting EMTs to rush to her side and wheel her backstage. The official WWE website later announced that she was resting at home after suffering from a heart arrhythmia, which was what caused her to pass out. Momma Benjamin returned to Raw the next week, but with an oxygen tank attached to her wheelchair that started being used as a weapon, especially on the February 20 episode when she led Shelton to winning the WWE Intercontinental Championship, in the process turning them both heel. Momma Benjamin was mentioned for the final time on WWE television on March 13, with Shelton announcing to the crowd that she was having heart surgery, and had no plans to return to WWE.
She provided the voice of Mammy Two Shoes in re-dubbed versions of Tom and Jerry from 1989 to 1992, replacing Lillian Randolph.
In 1999, Vidale appeared at the Philadelphia GLBT Pride Fest, her first GLBT event, with comic Etta May. Both were honored by the city's mayor, who officially named the day simultaneously "Thea Vidale Day" & "Etta May Day".
Vidale was announced as co-host for the 2009 AVN Awards, with Belladonna and Jenna Haze, on Saturday, January 10 at the Mandalay Bay Events Center in Las Vegas.
Vidale has spoken often about her troubled marriage where she suffered physical abuse from her husband. She had four children from that marriage and later left the kids with her ex-husband when she began touring around the country. She has spoken frequently about her faith in God. On March 26, 2009, Vidale was a guest on The Howard Stern Show on Sirius XM channel Howard 100, where she revealed that she has been with both men and women sexually. She appeared again on October 21, 2010, when she announced she had decided to have gastric bypass surgery because she had developed complications resulting from type 2 diabetes. She stated, "I have four children. This is not about vanity...I want it to be like a rebirth. A new me. A healthier me."