Jennifer Tilly was born September 16, 1958, in Harbor City, California. The daughter of Harry, a stockbroker, and Pat, a schoolteacher, Jennifer's parents got divorced when she was 6. Pat Tilly remarried and took Jennifer, her 3 siblings, and her 3 stepsiblings to British Columbia, Canada.

Having to relocate constantly with her family, Jennifer had to adjust to each new school, and was a pretty quiet student. At 17, she started out yet again at a new school, this time at St. Stephen's College in Missouri, to study theater. In order to help pay for her tuition, she contributed articles to magazines and earned money by winning Honorable Mentions in writing