Before bassist, singer, and songwriter Aaron Mills entered his teenage years, he was immersed in music through his father, a jazz saxophonist who played alongside Lionel Hampton and managed an eight-piece family band known as The Antiques. This group gained prominence in Asheville, performing sold-out shows and serving as the primary backing band for touring soul artists like Sam & Dave and Joe Tex. Mills and The Antiques regularly played regional gigs throughout the weekend, often rushing back to Asheville just in time for Mills to attend school at Asheville High School, where he played trumpet. Eventually, he shifted his focus to the bass, dedicating himself entirely to the instrument, which hindered his ability to maintain a regular job.

Mills' professional journey began with a tour alongside Chuck Jackson, an R&B singer from Pittsburgh who was signed to Motown and Scepter Records. He also recorded with Willie Hobbs, a Southern soul artist he had previously supported with The Antiques, which sparked his interest in session work. Mills describes these experiences as his "launching pad" for a career in music. He later moved to Durham to collaborate with trumpeter Donald Byrd, who was establishing a jazz program at North Carolina Central University. Byrd formed a septet called New Central Connection Unlimited, a funky jazz ensemble aimed at commercial success. The group toured for a year, promoting their 1977 album and single released by United Artists Records, and shared stages with acts like Cameo, where Mills' performance caught the attention of founder Larry Blackmon.

Following the disbandment of New Central Connection Unlimited in 1978, Mills felt disheartened but soon received a call from Blackmon inviting him to join Cameo as their bassist. The next day, Mills was flown to New York, where he rehearsed with the band for four hours before playing his first gig with them in Cleveland just 24 hours later. Mills became an integral part of Cameo's rhythm section alongside Blackmon, contributing to the band's dynamic performances. After five years with Cameo, he left in 1983 to form MCB with Cameo keyboardist Tommy Campbell and trombonist Jeryl Bright. While their sole release achieved limited success in the U.S., it performed better internationally. Following MCB, Mills recorded several singles for Sylvia Robinson's Sugar Hill label before rejoining Cameo in 1985, coinciding with the recording of their album Word Up. This release propelled Cameo to superstar status, with the title track reaching No. 6 on the Billboard Hot 100 and the follow-up single "Candy" topping the R&B charts in 1987. The album was certified platinum and led to collaborations with notable artists such as Miles Davis and Stevie Ray Vaughan.

Although Cameo's output slowed in the years following their prolific '80s catalog, they continued to release albums and tour. In 2000, after returning from Japan, Mills collaborated with Atlanta hip-hop duo OutKast, recording basslines for their tracks "Ms. Jackson" and "So Fresh, So Clean." He contributed to eight other tracks on their albums Stankonia and Speakerboxxx/The Love Below, including Grammy-winning singles "The Whole World" and "Hey Ya!" Mills briefly toured with OutKast and provided bass lessons to Andre 3000. His connections through Organized Noize producer Rico Wade also led to sessions with Cee-Lo Green, Bubba Sparxxx, and Gwen Stefani.

As Mills' commitments with Cameo have become less frequent, he has found opportunities to explore his musical interests through various projects. Since mid-March, he has performed every Sunday at Durham's Broad Street Cafe with a quartet that includes pianist Martin Eagle, guitarist Wayne Kee, and drummer Eric Mrozkowski. The group often features guest musicians, such as trumpeter Tom Browne, and plans to continue their performances. Mills is also eager to take his Aaron Mills Project on the road, encouraged by the support of local jazz enthusiasts. Additionally, he plays Thursday nights at Devine's Restaurant in Durham with guitarist Pat Madison and drummer Post Postlethwait as part of the rock-influenced ensemble On The Fly. In 2006, he produced local blues artist Bobby Hinton's album Liquor House Roots and is currently working on his own solo CD after years of collaboration. Mills also remains active in his church, playing two services at Durham's MJT Ministries whenever he is not on tour.