Linz was born in Santa Barbara, California, the son of Deborah Baltaxe, an attorney, and Dr. Daniel Linz, a professor of Communication at the University of California, Santa Barbara. His parents are divorced, and he lived with his mother. He has two younger sisters named Lily Alice and Livia. Linz's mother is of French- and Austrian-Jewish descent and his father is of German descent, and Alex had a Bar Mitzvah ceremony. He attended Alexander Hamilton High School in Los Angeles and graduated from the University of California, Berkeley, where he was a member of the improvisation and sketch comedy group, jericho!. In Linz's past, he was a lead science instructor at Galileo Learning, a pedestrian programs intern at City of Los Angeles, a strategy and planning department intern at Metrolink, and a legal researcher for Smith & Baltaxe, LLP.