Swedish international right-winger Mattias Jonson signed for Norwich on August 5th 2004 from Danish side Brondby for an undisclosed fee reported to be around £600,000. The former Helsingborg player signed a contract to take him until June 2006 with the option of a further year.

In 2003/4, he was a regular for Brondby as they finished second in the Danish league. A regular in the Swedish national team, he played three times at Euro 2004 scoring once against Denmark (who fielded Thomas Helveg) In total, he had 41 caps when he signed for the Canaries.

Mattias made his competitive debut for the Canaries on August 14th 2004 in the opening game of the 2004/5 Premiership season against Crystal Palace which finished 1-1.

In July 2005, Mattias returned to Sweden signing for Djurgarden for £700,000 on 16th July. In his first season with the club, he helped Djurgårdens IF win the Double of both the 2005 Allsvenskan and Svenska Cupen trophies

On10th May 2006, Mattias was called up for Sweden's World Cup squad and played in all four of his nation's World Cup games in Germany including the draw with England. He retired from international football in August 2006.

Jonson ended his career after the 2011 season, and played his last game on October 23, 2011. He had played 104 games for Djurgarden