Sydney Lemmon was born in Los Angeles and raised in Glastonbury, Connecticut. She received her Masters at the Yale School of Drama in 2017, where she was the recipient of the Julie Harris Scholarship. Lemmon also studied at the London Academy of Dramatic Arts and Boston University. She made her Broadway debut alongside Uma Thurman in The Parisian Woman in 2018. She is a singer and guitarist and writes music with her brother, actor Jon Lemmon.