He started his professional career playing for Hogaborg at the age of 17. He subsequently played for Helsingborg and Feyenoord. He was signed by Celtic in July 1997 for a fee of £650,000. His debut, playing Hibernian at Easter Road, was less than spectacular; he inadvertantly passed the ball to the other side, resulting in a 0-1 loss for Celtic.
Larsson has scored over 200 goals for Celtic and in 2001, he won the "Golden Shoe" award for being Europe's top goal scorer. In 2003 Sweden nominated Larsson as the greatest Swedish football player of the last 50 years. 
He is married, and has two children, Jordan (born 1997) and Janine (born 2002).