In 2006, he was transferred to Charlton Athletic. The following year he joined Bordeaux to strengthen the central defense with Marc Planus. Diawara was dropped from the Senegal squad in August 2006, ahead of their friendly with Côte d'Ivoire, due to a breach of discipline.
In July 2009, he signed a four year contract with Olympique de Marseille, with the transfer fee estimated at 7 million euros.
On August 8, he participated in his first game for his new club against Grenoble, which Marseille won 2–0.
On April 23, 2011, Marseille won the Coupe de la Ligue for the second consecutive year. Souleymane Diawara thereby became the player holding the record for most Coupe de la Ligue trophies, having won his first with Sochaux in 2004, his second with Bordeaux and his third and fourth trophies with Marseille.