Keirrison de Souza Carneiro (born 3 December 1988),[1] nicknamed "K9", is a Brazilian professional footballer who plays as a forward, most recently for Londrina.

Many teams throughout Europe were linked with Keirrison after hearing of Barcelona's plan to loan-out the Brazilian in order to acclimatize him to European football, including Roma,[13] Monaco and Ajax.

[14] In articles published several years following his arrival at Barcelona, Keirrison was chosen as one of the worst signings in the history of the club.

[15][16][17] On 28 July 2009, it was announced Portuguese Primeira Liga club Benfica agreed on terms to take the Brazilian on loan for the 2009–10 season.

[24] On 7 February 2010, just one week after being signed, Keirrison made his official debut for La Viola after coming on as a substitute for Manuel Pasqual in the 84th minute in a 1–0 loss against Roma.

[31] On 7 March 2014, Keirrison agreed a free transfer with Coritiba which was validated on 1 July, after his contract with Barcelona terminated.

[32] In September 2015, Keirrison went to court against Coritiba requesting unpaid wages and medical expenses from a surgery to recover from an injury.

[39] Keirrison was born in Dourados, Mato Grosso do Sul, the son of Operário (MS) footballer Adir Carneiro and Alzira Rosa de Souza.

His name was chosen by his father as a tribute to rock musicians Jim Morrison from The Doors and Keith Richards from The Rolling Stones, and also an admiration for the letter K.[3] Keirrison and his father bought a football club from Campo Grande, the capital of Mato Grosso do Sul in April 2008, and renamed it to Centro de Futebol Keirrison, shortened as CFK9.