Cannatella was born on November 4, 1979, and raised in Cut Off, Louisiana. She is of French and Italian ancestry. She was raised as a Southern Baptist, and has described herself as a "momma's girl". Her mother, a devout Christian, took her family to church three or four times a week. When she was 14, her mother died from a brain tumor. Cannatella was on several athletic teams throughout her high school career at South Lafourche High School. After visiting her sister Buffy at the University of Southern Mississippi, Cannatella decided on that college, which she began attending at age 17, though she never finished.

Sullen about the impending need to pay back her student loans as her graduation neared in 2002, Cannatella heard a radio ad for a show called Lost in the U.S., which offered a $50,000 prize. After auditioning for that project, she was invited to audition for The Real World: Las Vegas, the twelfth season of the long-running reality show, which would later air in 2002-2003. She accepted, but perceived the questions she was asked during the audition process to be part of an attempt by the producers to cast her as the stereotypical racist and homophobic southern cast member, and later, in light of the questions they asked about her religion, as the "holy roller". Cannatella was selected as a cast member. During her stay, she and her roommates worked in the hotel and clubs. Cannatella and her fellow castmates felt pressure from the producers to act out for the cameras in order to make appealing airtime, saying that she was asked leading questions by the producers about her plans on certain nights. She also notes that alcohol was made readily available to the cast, which she pointed out in light of the fact that alcoholism runs in her family.

In 2003, Cannatella was also a member of the Real World team during the Real World/Road Rules Challenge: The Gauntlet, but was sent home when she lost a gauntlet to Sarah Greyson. She also competed in the succeeding season, The Inferno, but was eliminated second. In May 2007, she appeared on the reunion show, Reunited: The Real World Las Vegas.

In 2005, Cannatella was a part of the reality show Kill Reality which chronicled the making of the movie The Scorned. She has also appeared in an episode of the reality show that pranks celebrities, Punk'd, hosted by Ashton Kutcher.

Cannatella appeared on Fear Factor in a special reality themed episode in 2006. Her partner was ex-boyfriend Mike Mizanin. The two competed against other teams of former reality contestants including Jonny Fairplay and Victoria Fuller. In the end, Cannatella and Mizanin won the show, taking home the prize money and several other prizes.

Cannatella appears in william Hung's music video for his single "She Bangs". During the 2007 Super Bowl, she appeared in a commercial for GoDaddy.com alongside former WWE Diva Candice Michelle. Later that year, she also appeared in the May 2007 issue of Stuff and on their website to promote her new television series VIP Passport, where she and several other girls fly to hot-spots around the world.

Cannatella is also a poker player. She finished third in the 2010 WPT Invitational Tournament and won $20,000.

In 2012, she returned to the Challenge and competed with former Real World housemate, Alton Williams, The Real World: Las Vegas (2011) alums Dustin Zito and Nany González in The Challenge: Battle of the Seasons; she and Zito finished the season in second place after Williams and Gonzalez were eliminated earlier in the season.

In 2016, Trishelle announced her engagement to John Hensz, who is a fighter pilot