Krakowski was born Jane Krajkowski in Parsippany, New Jersey. Her mother, Barbara (née Benoit), is a college theater instructor and producing artistic director for the Women's Theater Company, and her father, Ed Krajkowski, is a chemical engineer. She has an older brother. Krakowski's father's family is entirely Polish and comes from Kraków, and although she only knows a few words in Polish, her father and grandparents are fluent. Krakowski was a childhood classmate of astronaut Garrett Reisman.