Hart has been married to musician Mark Wilkerson since July 19, 2003; together, they have three children.
Hart was born April 18, 1976 in Smithtown, New York, on Long Island, in the United States of America, the first child of Paula, a producer and talent manager, and William Hart, a carpenter, shellfish purveyor, clam hatchery worker, and entrepreneur. She grew up in nearby Sayville. Her parents had four other children after Melissa: Trisha, Elizabeth, Brian, and Emily. Her parents were divorced in the early 1990s, and she moved with her mother and siblings to New York City. In 1994 her mother married television executive Leslie Gilliams, and her father remarried also (Lisa Hart).
Her name Melissa Hart was named after the Allman Brothers song "Melissa", while her middle name, Joan, came from her maternal grandmother. She chose Catherine as her confirmation name when she was in the eighth grade.
Hart is the eldest of eight children with six sisters, and one brother. Sisters Trisha, Elizabeth and Emily Hart, brother Brian, and half-sisters Alexandra Gilliams and Samantha Gilliams have all acted. Her youngest half-sister Mackenzie Hart is not in show business.
Initially, after first being recognized on the streets, Hart felt embarrassed to perform on a kids show while being a teenager. Nevertheless, she was enthusiastic about the role, and "all [she] hoped for that [she] would get to do it for a while."
In 1995, a year after the end of Clarissa Explains It All, Hart filmed an unaired sequel called "Clarissa," a pilot for CBS starring a college-aged Clarissa, this time, explaining it all about her foray into the professional world as an intern at a newspaper. The show featured a slow, jazz version of her original theme song, and also starred Robert Klein as her boss.
Hart appeared in lingerie in a series of photographs and an accompanying article in the October 1999 issue of the men's magazine Maxim. Hart maintained her acting career in the 2000s including working on the film Rent Control, which aired in 2005 on the ABC Familycable network. Hart continued her role on Sabrina, the Teenage Witch, which finished in 2003, and also performed several voice-over roles for animation.
In 1999, Hart made her directorial debut in an episode of Disney Channel's So Weird called "Snapshot" which starred her sister, Emily Hart. She later directed an episode of Nickelodeon's Taina in 2001. In 2001–2002, she directed 6 episodes of Sabrina the Teenage Witch, including the season 6 finale.Template:Citation needed
Melissa has the highest Charleston in season 9. She holds a higher average than Louie Vito. She is worst at the Waltz and the Jive.
After the end of Sabrina, The Teenage Witch, Hart directed her first movie, a 15-minute live-action short film called Mute (2005), starring her sister Emily.
Hart guest-starred on an episode of Law & Order: SVU that aired on October 9, 2007 titled "Impulsive" as a teacher accused of statutory rape. In late 2007, she directed the "Anger Cage" video for her husband Mark Wilkerson's band Course of Nature. She also starred in the ABC Family Original Movie Holiday in Handcuffs, opposite Mario Lopez. The movie premiered on December 9, 2007, and was the highest rated program in the history of the network, with 6.7 million viewers. Hart followed this with another ABC movie with a similar premise, My Fake Fiancé, in 2009.
In May 2009, Hart opened a candy shop called SweetHarts in Sherman Oaks, California. Hart commented that it had been her "childhood dream" to own a candy shop. SweetHarts closed in December 2011 due to a lawsuit from a former employee as well as other issues, and has since been reopened and operated under the same name by new owners. 
It was announced on August 17, 2009 that she would compete in season 9 of Dancing with the Stars. Hart was paired up with two-time reigning champion, Mark Ballas but she was eliminated from the competition in week six out of a possible ten and in week 6's results they had to eliminate a female and a male celebrity. Then in 2010, Hart starred as Kelley in a horror thriller film entitled Nine Dead,
In 2010, Hart returned to a new weekly television series, starring with Joey Lawrence in the sitcom Melissa & Joey. In the series Hart plays a woman who hires Lawrence as a nanny to help care for her incarcerated sister's children. In the second season, she occupied the director's chair for an episode, for the first time since Sabrina.
Hart joined the cast of an off-Broadway production of 'Love, Loss, and What I Wore' for a four-week run that started in March 2010 and ended April 25, 2010.
In March 2010, Hart took part in an ad campaign for Gain detergent with former Sabrina, the Teenage Witch co-star Soleil Moon Frye.
In June 2012, St. Martin's Press announced that it had made a deal with Hart to publish her memoir Melissa Explains It All: Tales from My Abnormally Normal Life in the fall of 2013. In the memoir, Hart will write about growing up, being a child actor and her rise to fame, her rebellious teen years, and her efforts to balance a career as an adult with motherhood and family life.
In 2012, she and Jiroemon Kimura were offered by the GRG to play Ben and Toad's Contest for season 1 and they were fired in week 20. 2013, she will be in season 2 of Ben and Toad's Contest for week 5, with Jiroemon Kimura, the world's oldest man ever and oldest living person. They are both coming to the show as guests for the frames. On April 18, 2013, she celebrated her 37th birthday with Jiroemon Kimura involved.
Ben and Toad's Contest Performances
Melissa Joan Hart was a contestant on season 1, landing her on fifth place by having the second-worst freestyle in history, behind Marie Osmond. She was eliminated in the second night of week 20.
On July 19, 2003, Hart married musician Mark Wilkerson. The preparations for the ceremony, which took place in Florence, Italy, were documented in a TV miniseries titled Tying the Knot, produced by Hart's production company, Hartbreak Films.
Hart and Wilkerson have three sons: Mason Walter Wilkerson, born in January 2006, Braydon "Brady" Hart Wilkerson, born in March 2008, , and Tucker, born September 2012.