Melissa Joan Hart (born April 18, 1976) is an American actress who is best known for playing the title roles in two successful television series, Clarissa Explains It All and Sabrina, the Teenage Witch.

Hart was born in Smithtown, New York, on Long Island, to Paula and William Hart, and grew up in Sayville, New York. Her stepfather (since 1994) is television executive Leslie Gilliams, and her stepmother is Lisa Hart. Hart was named after the Allman Brothers song "Melissa", while her middle name, Joan, came from her maternal grandmother. Hart chose Catherine as her confirmation name when she was in eighth grade.

Hart has three sisters, three half-sisters and one brother, all younger than she is. Her oldest sister, Trisha Hart, has worked as a producer. Sisters Elizabeth and Emily, brother Brian, and half-sister Alexandra Hart-Gilliams have all acted. Her two youngest half-sisters are not in show business.

Hart`s career began when as a three-year-old she made a television commercial for a bathtub toy called `Splashy`. From then on, she appeared regularly in commercials, making 25 of them before the age of five. Other early television work included a small role in the miniseries Kane & Abel in 1985, a guest-starring role in an episode of The Equalizer in 1986, and a starring role alongside Katherine Helmond in the Emmy Award-winning TV movie Christmas Snow, also in 1986.

In 1989, she auditioned for a Broadway production of The Crucible starring Martin Sheen, becoming an understudy to three of the young girls in the play. This paved the way for her to land the title role in the TV show Clarissa Explains It All. The Nickelodeon series, a comedy about a teen girl in everyday situations, became a big hit during its four-year run. The show made her a household name among American teenagers and brought her four consecutive Young Artist Award nominations, of which she won three.

Hart also recorded two albums as Clarissa, This is What `Na Na` Means and a recording of Peter and the Wolf (Sony Classical SK 64079). The former, a rock/pop album in the style of a garage band, was mostly a novelty product and did not receive much attention from critics or the public. The latter album won a Parents` Choice award.

After the television series was canceled, Hart attended New York University. She did not complete her degree, however, since she soon resumed her acting career when she got the lead role for the 1995 TV movie Sabrina, the Teenage Witch. This was followed by the television series of the same name which lasted seven seasons. In between, she also guest-starred on the series Touched by an Angel and starred in several TV movies.

In 1998, Hart landed a small part in the movie Can`t Hardly Wait, and then started filming Next to You, starring alongside Adrian Grenier. Hart asked friend Britney Spears to do a remix of her song "(You Drive Me) Crazy" and add it to the movie`s soundtrack. To capitalize on the song`s success as a top-ten hit, the title of the movie was changed to Drive Me Crazy and Hart joined Spears in the music video for that song. Around the same time Spears also did a guest role, playing herself, on an episode of Sabrina.

Hart appeared in lingerie in a series of photographs and accompanying article featured in the October 1999 issue of the men`s magazine Maxim.

In 2001-2002, she directed 6 episodes of Sabrina the Teenage Witch, including the season finale. In 2005, Hart directed her first movie, a 15-minute live-action short called Mute, 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 Fiance, in 2009.

In March 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.

It was announced on August 17, 2009 that she would compete in season 9 of Dancing with the Stars. She is paired up with two-time reigning champion, Mark Ballas. On October 27, Melissa was eliminated from the competition, finishing ninth out of sixteen.