Tyler was born in San Francisco, California, the daughter of Robin Gregory, a teacher, and Jim Tyler, a photographer. Her parents divorced when she was 10 and she was raised by her father. She pursued an early interest in comedy during high school, when she would skip her regular courses to attend local comedy improv classes. She also attended theater classes at San Francisco's School of the Arts High School. She attended Dartmouth College where she earned a degree in government with a minor in environmental policy and was a member of The Tabard, a co-ed fraternity. At Dartmouth, she co-founded and sang in the all-female a cappella group, The Dartmouth Rockapellas, a group devoted to spreading social awareness through song. After briefly working for a San Francisco advertising firm, she toured the country pursuing a comedy career before finally moving to Los Angeles, California in 1996.