Alexander is best known for his role as George Costanza in the television series Seinfeld. Other well-known roles include Phillip Stuckey in the film Pretty Woman (1990) and the title character in the animated series Duckman (1994–1997).\n', '
Alexander has had an active career on stage, appearing in several Broadway musicals including Jerome Robbins\' Broadway in 1989, for which he won the Tony Award as Best Leading Actor in a Musical. He appeared in the Los Angeles production of The Producers. He was the Artistic Director of "Reprise! Broadway\'s Best in Los Angeles", where he has directed several musicals.\n', '
Alexander was born in Newark, New Jersey, the son of Jewish parents Ruth Minnie (née Simon), a nurse and health care administrator, and Alexander B. Greenspan, an accounting manager whose first name Jay later borrowed to create his stage name. He has a half-sister, Karen Van Horne, and a half-brother, Michael Greenspan. Alexander grew up in Livingston, New Jersey, and is a 1977 graduate of Livingston High School. He attended Boston University but left the summer before his senior year, after getting work in the city of New York. At Boston University, Alexander wanted to pursue classical acting, but a professor redirected him toward comedy after noticing his physique, remarking, "I know your heart and soul are Hamlet, but you will never play Hamlet." He was awarded an honorary degree in 1995. He is a practicing magician, and switched to acting as a career only after deciding that he was unlikely to succeed professionally in a magic career.\n', '