Birbiglia was born in Shrewsbury, Massachusetts, the son of Mary Jean and Vincent Paul Birbiglia. He is of part Italian descent. Birbiglia attended St. John's High School, Shrewsbury, Massachusetts for one year, and graduated from St. Mark's School, Southborough, Massachusetts in 1996 and subsequently graduated from Georgetown University in 2000. During college Birbiglia performed as a member of the Georgetown Players Improv Troupe.