Simpson was born in Lomé, Togo, to a Togolese father and a German mother, moved to Sweden at the age of six and was raised on Ekerö, Stockholm.
[1] He won the JSM för klubblag with the IF Brommapojkarna youth squad in 1989 and made his senior debut in 1990.
[7] Simpson made his full international debut for the Sweden national team on 9 February 1997 in a 2–0 friendly win against Romania, playing for 67 minutes alongside Marino Rahmberg at forward before being replaced by Robert Steiner.
[8] He won his second and last cap four days later in a friendly 1–0 win against Japan, playing for 76 minutes before being substituted by Daniel Andersson.
[10] In December 2015, it was announced that Simpson was taking over Swedish third-tier team Vasalund after Roberth Björknesjö.