Steven Siro Vai (; born June 6, 1960) is an American guitarist, composer, singer, songwriter, and producer. He was voted the "10th Greatest Guitarist" by Guitar World magazine, and has sold over 15 million records. A three-time Grammy Award winner and fifteen-time nominee, Vai started his music career in 1978 at the age of 18 as a transcriptionist for Frank Zappa, and joined his band from 1980 to 1983. He embarked on a solo career in 1983 and has released eight solo albums to date.

Steve Vai, a descendant of Italian immigrants, was born in Carle Place, New York on June 6, 1960. He is the fourth son of John and Theresa Vai. He described his first experiences with music as, "at the age of five I walked up to [a] piano, hit a note, and noticed that to the right the notes go higher and to the left the notes go lower. In that very moment, I had a full-on epiphany. I was flooded with the instinctual realization of how music was created and how it worked from a theoretical standpoint--the whole language of music was very obvious. I also understood immediately, instinctually, and unequivocally something that has only deepened through the years that the creation of music is an infinite personal expression. I realized that I could do this, I could make music, and it could be whatever I want."  It was a year later, at the age of six, that Vai experienced his first introduction to the guitar, remembering that, "I saw this nine-year-old boy playing the guitar in my grade school auditorium, and that was another epiphany that I had. It was my first recognition of the instrument. When I saw that guitar and I saw this kid playing it, I knew instinctually that I was going to play the guitar someday, and that it would be my instrument. Don't ask me how I knew, I just knew. It was the coolest thing I had ever seen."  As a young child, Vai was influenced by the music his parents had listened to. One album in particular that he cites as his "musical awakening" was the original motion picture soundtrack to the 1961 film West Side Story. At age eleven, Vai was introduced to the contemporary rock and progressive music of the era, and after hearing the guitar solo to Led Zeppelin's "Heartbreaker" at age twelve, decided to begin playing the guitar.  In 1973, Vai began to take guitar lessons from fellow New York native Joe Satriani, and played in local bands (The Ohio Express, Circus, and Rayge) throughout his high school years. Vai cites artists such as Jimmy Page, Brian May, Ritchie Blackmore, Jeff Beck, Jimi Hendrix, as well as jazz fusion guitarists Allan Holdsworth and Al Di Meola as some of his major influences in that time period. In 1978, to further pursue his interest in music composition and theory, Vai attended Berklee College of Music in Boston, Massachusetts. While at Berklee, Vai began working for Frank Zappa as a transcriptionist, and in the middle of his fourth semester, moved to California to start his career as a session and touring artist for Zappa. Also while at Berklee, Vai met his future spouse Pia Maiocco, with whom he has been together since; they have two children. In 2000, Vai was awarded an Honorary Doctorate of Music from Berklee.

Does he have any siblings?
He is the fourth son of John and Theresa Vai.