Okereke was born in Liverpool to Catholic Igbo Nigerian parents. His mother was a midwife, and his father a molecular biologist. He grew up in London with his sister. As a child, he went to school at Ilford County High School (where he was known as Rowly), but switched to Trinity Catholic High School, Woodford Green for sixth form at age 16. He lived in Bethnal Green, and in 1998 he became friends with a student of nearby Bancroft's School, Russell Lissack, who would become Bloc Party's guitarist. A year later, while studying at King's College London, Okereke met Lissack again at Reading Festival, where the band was officially formed under the title of 'The Angel Range'. In 2001, Okereke moved out of his parents' home. He went on to meet Gordon Moakes and Matt Tong who became the band's permanent bass guitarist and drummer, respectively. In 2003, the band changed its name to Bloc Party after briefly being called Union.
In 2005, Bloc Party released their first studio album, titled Silent Alarm. The album reached number three in the UK charts, and propelled the band to fame. Despite this, Okereke continued to study English literature at university. Until the release of Silent Alarm, he had kept his musical activities secret from his parents.
The band released their second album A Weekend in the City on 5 February 2007 in the UK and 6 February in the US. The album debuted at #12 in the Billboard 200 with 48,000 copies sold, and reached the #2 spot in the Official UK Chart.
It became available via the UK's iTunes Store a day ahead of schedule, on 4 February. The first single, "The Prayer", was released on 29 January, having been made available on Myspace on November 22, 2006. It reached #4 on the UK Singles Chart, still the group's highest placing. The next single, "I Still Remember", was the album's first in the US. The album was produced by Jacknife Lee.
In the build up to the release of the album, Zane Lowe aired a live set from the BBC studios at Maida Vale featuring a mix of old songs and new ones on his evening radio show on BBC Radio 1 on 30 January 2007. The band also scheduled their first gig with the second album at Reading Hexagon to coincide with the UK release date. On 1 February 2007, A Weekend in the City was made available to listen to for free through the band's official Myspace website.
The third album released by the band Intimacy, was initially only made available for purchase on their website as a download on 21 August 2008. The record was released in compact disc form on 24 October 2008, with Wichita Recordings as the primary label. It peaked at number 8 on the UK Albums Chart and entered the Billboard 200 in the United States at number 18.
The band went on hiatus as of 31 October 2009.
Okereke moved to Berlin to seize the city's music oriented spirit.
Okereke makes a guest appearance on Tiësto's song "It's Not the Things You Say" on his album Kaleidoscope, released October 6, 2009.
Okereke released his first solo album, titled The Boxer, produced by XXXChange, on 21 June through Wichita / Polydor in the UK and Europe and Glassnote Records for the rest of the world. Okereke explained the album title, saying "as a boxer, you have to rely on nobody else but yourself to achieve what it is you want to achieve. Even though you take hits, you have to keep focus on your priorities and keep going. I thought that was an inspiring image." The first single from the album, "Tenderoni", was released on 14 June 2010.
On September 13, 2011, NME and Wichita Recordings announced that Kele would be releasing a follow up to The Boxer; an EP titled The Hunter.