Kewullay was born and raised in Fourah Bay, a neighbourhood in Freetown, Sierra Leone to Limba parents. He attended the Albert AcademySecondary school in Freetown. Conteh first moved to Italy in November 1995, joining Serie A team Atalanta from Swedish side FC Café Opera. He played two times for Atalanta, all in his first season with the nerazzurri, making his debut in a 1–0 loss against Fiorentina on 20 April 1996. After a short stint back to FC Café Opera, Conteh then joined Serie B side Chievo Verona on January 1998. He played three seasons for the flying donkeys, before signing for Venezia in 2000. After two seasons for Venezia, one in Serie B and one in Serie A, Conteh, together with many other team players, left Venezia for Palermo in 2002 after chairman Maurizio Zamparini bought the Sicilian team. He played for Palermo since then, initially as a regular, and later as a backbench player. Kewullay Conteh made his debut in the 2005–2006 season on January, after having been ignored by coach Luigi Delneri during all his time in Palermo, and however being reconsidered by substitute Giuseppe Papadopulo, who made him play first in a UEFA Cup match played away against SK Slavia Praha, in which Conteh scored a goal. After a number of impressive showings, Conteh renewed his contract for Palermo, which was due in June 2006, for two more years. On August 2006 he was loaned to Atalanta B.C., but failed to break into the starting lineup in the 2006–07 season. On August 2007, he rescinded his contract with Palermo and joined Serie B sideAlbinoLeffe in a free transfer, signing a one-year-long contract with the seriani. He left AlbinoLeffe in June 2008, as he initially failed to agree for a new contract, but re-joined the team on September as a free agent. He is also a regular for the Sierra Leone national football team. In December 2011, Conteh was confirmed to be under investigation from the Magistrature of Cremona for briberies related to the 2011 Italian football scandal, being accused to have agreed to fix a number of Serie B football games while at AlbinoLeffe together with teammates Filippo Carobbio, Paolo Acerbis and Joelson.
