After the end of Sabrina The Teenage Witch, Hart directed her first movie, a 15-minute live-action short film called Mute. Hart's career has mixed movie work with television including appearances in the popular TV shows Law and Order and That '70s Show. In March 2009, Hart opened a candy shop called SweetHarts in Sherman Oaks, California. Since 2010, Hart has starred in the ABC Family series Melissa & Joey.
In 2002, Rhea landed her own daytime talk show, The Caroline Rhea Show. In 2004, Rhea became the first host of the series, The Biggest Loser on NBC, In 2005, Rhea was in the movie The Perfect Man, She appeared as a contestant in 2001 on a special edition of Who Wants to Be a Millionaire, winning $125,000 for charity. She had her own stand-up special as part of Bravo's three-part Funny Ladies series, Rhea has had a recurring role on the hit Disney Channel Original Series, The Suite Life of Zack and Cody .
She now does the voice of Linda Flynn in Phineas and Ferb, an animated show with Ashley Tisdale. Rhea will next appear on the upcoming Fox animated series Two Dreadful Children.
Her television credits include Married With Children, The 5 Mrs. Buchanans, Hearts Afire, Supernatural and Glory Days. She also had a minor, recurring role in the hit ABC series, Lost and also played a minor role in CSI: Miami more recently, she had guest starring roles on Leverage and Castle.
She has also appeared in several theater productions like Carnal Knowledge, Triplets in Uniform and Zastrozzi, the Master of Discipline (which she also co-produced). In New York she has starred in The Mousetrap, The Lion in Winter and many more. She was recently in the Chicago Northlight Theatre production of the one woman show titled Bad Dates. She has also played a role in Women: Stories of Passion. In 2011 she will star in The Muppets, Bad Actress and Fly Away.