Two years later he accompanied a friend to an audition for Pure Prairie League. The band members remembered Gill because his high school band Mountain Smoke had opened for them years before, and immediately offered him a job. In 1979, he became the band's lead singer. During his three years with them, the band had a Top 40 pop hit with his song, "I'm Almost Ready" (1980). He left Pure Prairie League soon after the single's success to spend time with his then-pregnant wife Janis Oliver, a well-known bluegrass singer on the West Coast. After the birth of the child, Gill contacted Rodney Crowell to see if his band the Cherry Bombs needed a guitarist. He joined Crowell's group and, shortly afterward, former Cherry Bomb keyboard player Tony Brown signed Gill to a solo contract at RCA.

In 1984, Gill moved his family to Nashville and cut his debut EP, Turn Me Loose. His second single, "Victim of Life's Circumstances," cracked the country Top 40, beginning a string of hit singles that ran well into the '90s. In 1985, Gill had two Top Ten hits including "If It Weren't for Him," which featured harmonies from Rosanne Cash. In addition to his hit singles, Gill sang harmonies and played guitar on over 120 records, wrote and co-wrote songs with artists like Rosanne Cash, and toured with Emmylou Harris's band during the latter half of the '80s. In 1989, his career fired up again after he signed with MCA. His first album with the label, When I Call Your Name, produced the Top 25 hit "Never Alone," a song co-written with Cash. Following "Oklahoma Swing," a hit duet with Reba McEntire in 1990, Gill released "Never Knew Lonely," a number three hit in the fall of 1990 that began a string of Top 10 hits that ran for five straight years.

Gill's 1991 album Pocket Full of Gold went platinum a year after its release, and more hits and accolades followed.

By the time he was asked to joined the Grand Ole Opry in 1992, Gill had become a bonafide superstar -- his '92 album I Still Believe in You went platinum within two months of its release. He had three Top Three hits in 1993, including "One More Chance." In 1993, Gill's RCA best-of album went gold, as did his Christmas album Let There Be Peace on Earth. In 1994, he released When Love Finds You, which hit the Top Three on the country album charts and crossed over to land on the Top Ten pop album chart. In June of 1996, Gill released High Lonesome Sound; The Key followed two years later, as did the seasonal collection Breath of Heaven.