Walker was born in Örebro, Sweden, and started his football career in Varbergs BoIS. Son of the former Örebro SK manager Patrick Walker, Kevin made his senior debut for Superettan team Örebro SK in the 2006 season. Örebro SK was promoted to Allsvenskan and Walker made his Allsvenskan debut in the following season. From 2007 to 2011, Walker was in the AIK organisation, having loan spells to Väsby United, Assyriska Föreningen and GIF Sundsvall. He moved to GIF Sundsvall at the end of the 2011 season. Walker played for Superettan side GIF Sundsvall which he vice-captained during the autumn 2013. After the 2014 season, Walker signed a contract with Djurgårdens IF and was presented on 5 November 2014. In March 2016 Walker was appointed captain for Djurgårdens IF. On 10 May 2018 he played as Djurgarden beat Malmo FF 3-0 in the Swedish Cup Final.
Kevin Walker has been fascinated with music from a very young age; ever since he heard his Irish grandfather sing.
In ''Idol''
In 2013, he auditioned to the Swedish Idol 2013 with the song "Soldier". The series in its ninth season was broadcast on TV4. His whole Idol adventure began after a video of him jamming with a teammate at a football club function caught the attention of the show's producers. A few of Walker's football league games for GIF Sundsvall were moved to avoid a clash with his television commitments during Idol. Walker reached the final alongside Elin Bergman, with both of them singing the winning song "Belong". Walker won by popular vote. His winning prize included a recording contract with Universal Music Sweden. In the final show, he and Bergman joined Robbie Williams in singing Williams' song, "Shine My Shoes". ;Performances
Audition: – "Soldier"
Bootcamp heats: – "Use Somebody"
Week 1 – "Pride"
Week 2 – "Say"
Week 3 – "Poker Face"
Week 4 – "Behind Blue Eyes"
Week 5 – "Hope and Glory" –
Week 6 – "It's My Life"
Week 7 – "Till dom ensamma" and "Välkommen in"
Week 8 – "Don't Look Back in Anger" and "Hall of Fame"
After winning the title, he was signed to Universal Music as part of the award, and released his debut single, the winning song "Belong" that subsequently charted on Sverigetopplistan, the official Swedish Singles Chart. Walker's debut studio album, also titled Belong, peaked at number 2 on the Swedish Album chart. In late December 2013 Walker was interviewed in the talk showThe Late Late Show on RTÉ while visiting Ireland. He performed "Where the Streets Have No Name" during the show.