Poehler was born in Newton, Massachusetts. Her parents are high school teachers Eileen Frances (née Milmore) and William Grinstead Poehler. She grew up in nearby Burlington. Her father is of German, Irish, Portuguese, and English ancestry. Her mother is of Irish ancestry. Poehler was raised in the Catholic faith. She graduated from Burlington High School in 1989. She studied at Boston College and at The Second City.