Julio Fernández was born August 29, 1954, in Havana, Cuba, but grew up in Hoboken, New Jersey, where he started guitar at nine, taught by his jazz- and big-band-loving father. He graduated from Hoboken High School in 1972 and enrolled at Montclair State University on a music education scholarship, but dropped out after one semester of his second year to pursue a career as a working musician.

By 1984 his career had stalled. His friend and collaborator Gerardo Velez, then Spyro Gyra's percussionist, told him the band needed a new guitarist. Fernández auditioned and was hired the next day, replacing Chet Catallo. Apart from a two-year hiatus at the end of the 1980s, he has held the guitar chair ever since, appearing on 24 of the band's 31 albums, composing more than 30 songs for the group, and touring in more than 70 countries. The band's own story is told in full in Spyro Gyra's JazzProfiles.com profile.

Fernández's guitar work, rooted in a childhood steeped in jazz and big-band records via his father, brought a distinct melodic voice to Spyro Gyra's sound across four decades, one of the longest tenures of any non-founding member of the band.