Porter was born in Worcester, Massachusetts. She is Jewish;[1] her maternal grandmother, whose father-in-law Joseph Klein was a prominent Worcester rabbi, ran the Charlotte Klein Dance Center in Worcester.[2] Porter's mother, Laura Klein, was a dance coach for Diane Klimaszewski and Elaine Klimaszewski, who appeared on Star Search in 1987, in the junior vocalist category, before they became better known as the Coors Light Twins. Her father, Ric Porter, was co-founder, lead singer, and songwriter of the Worcester Band Zonkaraz.[3] While in Los Angeles for the twins' appearance on the show, the show's producer heard Porter singing in the hotel lobby and had her on the very next episode. Alisan has been singing and performing since the age of three; at the age of five, she became the youngest Star Search participant ever to win the competition.
As an actress, she is known for her lead role as Curly Sue in the 1991 movie Curly Sue starring Jim Belushi.
Porter continued acting in high school in Westport, Connecticut, where she joined a theatre group and participated in various shows. When she was eighteen, she moved to New York to audition for Broadway shows. She was cast as Urleen in the show Footloose.
Porter is based in Los Angeles, where she has been working on her music career. During this time she starred as Miriam in the smash The Ten Commandments: The Musical at the Kodak Theater in Los Angeles alongside Val Kilmer and Adam Lambert and Broadway star Lauren Kennedy. In 2003, the band The Raz was formed, with Porter as the vocalist and main songwriter. The Raz split up in 2004. In March 2005, she announced the birth of her new band, The Alisan Porter Project. During 2006, she performed in the 2006 revival of A Chorus Line as Bebe Bensonheimer at the Gerald Schoenfeld Theatre in New York City.
On October 9, 2009, Porter's independent debut self-titled album was released. Porter's friend Scarlett Cherry wrote and produced the album.