Finnish international Jonatan Johansson joined Norwich City on loan from Charlton Athletic on 31st January 2006 until the end of the 2005/6 season. Nigel Worthington admitted that "Johansson is a player we have monitored for some time - but the scenario would need to be right for things to happen.”

JJ, as he is known at the Valley, joined Charlton from Rangers in July 2000. The Finnish international had scored 24 goals in just 36 starts at Ibrox, and ended his first season in the Premiership as the Addicks' top scorer with 14 goals. However his goal scoring tally had slipped. During 2004/5, he scored four times in thirty starts -and two of those were against Norwich. During 2005/6 the signing of Darren Bent had limited his chances and he had made just six appearances, scoring once. His record for Charlton reads 33 goals in 167 games while he has scored nine times in 43 outings for his country. He began his career with Finnish sides TPS and Flora before joining Rangers in 1997.

He made his Norwich debut as a substitute in the 4-0 away defeat to Reading on 31st January 2006.His full debut came on 5th February in the 2-1 defeat to Ipswich at Carrow Road. Jonatan scored Norwich's goal.

Returning to the Valley at the end of his loan, he was released along with Shaun Bartlett and Francis Jeffers in May 2006 when their contacts came to an end. Although it was though that Norwich would add JJ to their squad, instead he signed for Swedish side Malmo in eary July 2006.

On 31st January 2008, the Scotsman reported that "Hibs are thought to have had a £150,000 bid rejected for former Rangers striker Jonatan Johansson, who now plays for Malmo"

Hibs finally got their man when they announced in mid-November 2008 that they had signed a pre-contract agreement with Finnish international striker Jonatan Johansson. He will join the Edinburgh side in January 2009 once his contract with Swedish side Malmo expires. JJ joined Hibs on 1st January 2009 and made his debut two days later against Hearts in the Edinburgh Derby.

Along with David van Zanten and Patrick Deane, Johansson was released by Hibs on 1st September 2009. He signed a short-term contract with St Johnstone on 27th October 2009 until January 2010. After 5 appearances and 1 goal for St Johnstone, he was released on 7th January 2010 and was expected to sign for Greenock Morton. Instead, he returned to Finland to sign for former club TPS on 10th February 2010

Jonatan announced his retirement from professional football on 23rd March 2011 and took up a poisition as youth coach with Greenock Morton almost a year later. He moved to Motherwell in August 2012 to coach their under-20 team

He subsequently joined Rangers on 17th April 2017 as part of Pedro Caixinha's backroom ream. Caixinha said ""We had a fantastic list of candidates and it really was really a pleasure. We tried to fill three major points and it wasn't an easy decision. First of all, we wanted someone with a Rangers past. The second point was of course to know the Scottish reality of football and the third, which was also important and which makes all the difference, is to align with our dynamic, our processes and our methodologies. We chose Jonatan and we believe in him. He will be a good assistant to add to our team because he's a quality guy, he is a hard worker and he is clever.I want all of the assistants to share with me the responsibility of what it means to be managing this club."

He returned to Morton on 6th September 2018 as their new manager. Johansson left Morton at the end of the 2018–19 season, as the club decided not to exercise the option of retaining him for the second year of his contract. He had won 9 of his 34 games in charge (26%).

On 24th July 2020 he was appointed manager of TPS Turku on a two year contract. He was dismissed on 25th September 2022.

In early 2023 he returned to Rangers as a coach with the Under-16s. Since January 2024 he has coached their Under-18s.

He was capped 106 times by Finland between 1996 and 2010, scoring 22 goals.