Giannascoli was born in 1993 in Havertown, Pennsylvania. His father's family originates from Abruzzo in central Italy. At age 11, he learned how to play his brother's guitar and began recording music. While attending Haverford High School, Giannascoli made two albums that he shared with friends. He experimented with different musical styles while making collaborative music, which included the "goth techno" he made with his sister in their band MOTHER, as well as the projects involving his high school band The Skin Cells, described as "pop rock that accidentally ended up being punk". In 2011, Giannascoli enrolled at Temple University, where he studied English in hopes to become a teacher, but eventually dropped out to pursue a musical career.