A finalist in the 1970 Miss America Pageant, Hart was born in Sioux Falls, SD and raised in the USA and Europe. She attended boarding schools and college in South Dakota. After representing her home state as Miss South Dakota, she taught high-school English before trying her hand at showbiz. Relocating to Iowa, she entered broadcasting with a public-service radio and TV program. By 1976, this genial blonde had moved to Oklahoma City, where she served as a producer and host on a popular morning interview show. Tapped to host the L.A. edition of "P.M. Magazine" in 1979, Hart moved West. Three years later, Regis Philbin selected her to co-host his NBC show. Within a year, Hart was behind the desk at "Entertainment Tonight".

In addition to her duties as host and interviewer on "ET", Hart has developed a secondary career as a singer-dancer, performing in Las Vegas, Atlantic City and other venues. She performed for President and Mrs. Bush at the White House and has been actively involved in numerous charitable functions, notably the Children's Miracle Crusade. Since 1989, she has been married to executive and businessman Burt Sugarman.