 In 2007, Semedo signed a four-year deal with Charlton Athletic on a free transfer.Although touted as a central defender when he signed, he played mainly as a defensive midfielder for the Football League Championship club, and scored his first goal for the side in a 4–0 win over Tranmere Rovers on 29 August 2009, with Charlton now in League One.Semedo was crowned "Charlton's Player of the Year" in May 2011, picking up 43% of the votes in what was the club's worst season for a number of decades.