Walters was born in Peckham, London. He was raised by his mother, Pamela Case, a local government officer. He attended the Sylvia Young Theatre School from the age of 6. After graduating, Walters starred in some popular stage productions of the time.
Musically, he is best known as Asher D in the group So Solid Crew. He enjoyed relative success as a lyricist, particularly for their number 1 hit "21 Seconds". After the group split, he went on to focus on other projects, most recently 2006's In Memory of the Street Fighter, featuring the single "Andrea". He released a studio album in 2008 entitled The Appetiser, a 12-track album produced by both him and Laurence Ezra. With Dewi Bruce Konuah, he co-owns a production company called AD82 Productions, specialising in talent in the British music and film industries. Early 2012, he signed a recording contract with the independent record label, SK Records, founded by the British singer-songwriterSimon Webbe and his business partners Karan and Preeti Singh. Ashher's single "How You Like Me Now" was released on 29 July 2012. In November 2012, Asher appeared on Radio 1 DJ Charlie Sloth's "Fire in the Booth" show, while on 12 November 2012 his second single for SK "Your Love" was released and featured vocals from Alesha Dixon.
Walters is also an actor, appearing under his full name, Ashley Walters. He appeared as Omar in The Young Indiana Jones Chronicles at the age of 10, and as Andy in Grange Hill at the age of 14. He appeared in Bullet Boy, where he played Ricky who had just came out of jail to start a new life, a role for which he was named Best Newcomer at the British Independent Film Awards. He also appeared in Get Rich or Die Tryin'.
For the BBC Learning project "Off By Heart Shakespeare", Walters delivered one of Shakespeare’s best known speeches, "But soft, what light through yonder window breaks?" from Romeo and Juliet. In October 2011, Walters starred in the Arjun Rose slasher Demons Never Die. From 31 October 2011, he played Dushane in a four part drama Top Boy. In February 2012, he played Chris in the BBC drama Inside Men. In 2013 Walters reprised his role as main character Dushane in the second series of Top Boy.
Ashley married Danielle Isaie on 22 June 2013. Walters has two sons (Paniro and Shayon) and one daughter (China) with ex-partner Natalie. He also has two daughters(Antonia, Ashleigh) with Lisa Slone, a girl who recently lived in Hither Green South East London In July 2001, following an argument with a traffic warden, he was found to be carrying a loaded Brocock air pistol modified to fire live ammunition. He was arrested and, in 2002, jailed for 18 months, in a young offenders' institute. Having spent the previous nine months in custody, he subsequently served an additional nine months to complete his sentence. On 31st March 2014 he was fined £600 after he admitted assaulting a security guard in Aberdeen in September 2013.