[7] In 1991, Hart landed the starring role on the Nickelodeon series Clarissa Explains It All, a comedy about a teenaged girl in everyday situations, which was successful during its four-year run.

[10] Her role in the series also led to her starring in the FMV video game Nickelodeon's Director's Lab as a tour guide who takes the player around a film studio.

[citation needed] Initially, after first being recognized in public, Hart felt embarrassed to be acting in a children's show while being a teenager.

[14] Hart appeared on Nickelodeon's anthology show Are You Afraid of the Dark?, in the Season 2 episode "The Tale of the Frozen Ghost" (1993).

[23] Coinciding with the release of Drive Me Crazy, Hart appeared wearing lingerie on the cover of Maxim magazine's October 1999 issue, as well as in a photo shoot and an accompanying article, which resulted in an attempt by the publisher of the Sabrina comic book series to sue her for breach of contract.

[24][25] Hart continued her acting career, starring in the film Rent Control, which aired in 2005 on the ABC Family cable network.

In 1999, Hart made her directorial debut in an episode of Disney Channel's So Weird called "Snapshot" which guest-starred her sister Emily.

In 2007, Hart guest-starred on an episode of Law & Order: Special Victims Unit titled "Impulsive" as a teacher accused of statutory rape.

[1][32][33] In the series Hart plays a woman who hires Lawrence as a nanny to help care for her incarcerated sister's children.

[35] 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.

[36][37] In March 2010, Hart took part in an ad campaign for Gain detergent with Sabrina, the Teenage Witch co-star and friend Soleil Moon Frye.

[39] 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 wrote 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.

[40] In 2013, Hart attempted to use crowdfunding (via Kickstarter) to fund a romantic comedy film to be titled Darci's Walk of Shame, but was only able to garner $51,605, or just 2.6% of the expected $2 million goal.

[45] In January 2022, Hart began hosting a podcast titled What Women Binge starring her and her friend Amanda Lee.

[56] The preparations for the ceremony, which took place in Florence, Italy, were documented in a television miniseries titled Tying the Knot, produced by Hart's production company Hartbreak Films and aired on ABC Family.

[63] Hart wrote a diary, including video entries, to document potty training her son, Mason, for Huggies Pull-Ups brand diapers.

[65] Hart was near The Covenant School in Nashville when a mass shooting occurred there in March 2023 and helped escort some of the fleeing children to safety.

[66][67] She later recounted the experience on NewsNation and her social media accounts, while noting that she and her children were also in proximity to the Sandy Hook Elementary School shooting in 2012.

[69][70][71] Hart has expressed support for increased gun control, marching in a Moms Demand Action demonstration in Brooklyn in May 2016.