Emmerich was born to a Jewish family, the son of Constance, a concert pianist, and Andre Emmerich, a Frankfurt-born gallery owner and art dealer. Emmerich's brother, Toby Emmerich, is president and chief operating officer at New Line Cinema and a screenwriter as well, and his brother, Adam Emmerich, is a leading mergers & acquisitions lawyer at the firm of Wachtell, Lipton, Rosen & Katz in New York. Noah was previously married to actress Melissa Fitzgerald.
He studied the Meisner technique of acting privately under Ron Stetston, a prominent actor-director who is currently senior member of the acting staff at the Neighborhood Playhouse in New York City. He is a graduate of Yale College, where he majored in History and sang in the Yale Spizzwinks a cappella singing group.