Weigert was born in Washington, D.C., the daughter of Dionne Laufman and Berlin-born Wolfgang Oscar Weigert, a Psychiatrist. She is Jewish. After graduating from Brandeis University in 1991, Weigert attended New York University, earning a Master of Fine Arts degree in the Graduate Acting Program at the Tisch School of the Arts. After a decade as a stage Actress based in New York City, she moved to Los Angeles and has appeared in various movies, TV shows and mini-series.