The former Sweden striker won two LaLiga titles, the Supercopa de Espana and the UEFA Champions League during a two-year spell at Camp Nou as a player.
Larsson scored 22 goals in 62 appearances in all competitions but is perhaps most fondly remembered for coming off the bench to set up both Barca goals as it beat Arsenal 2-1 to become champion of Europe.
👋 Welcome back, Larsson! 🇸🇪 pic.twitter.com/JgyDbW4mgo— FC Barcelona (@FCBarcelona) August 21, 2020
The former Celtic and Manchester United forward, who was head coach at Helsingborgs last year, has signed a two-year contract at Camp Nou.
Joining Larsson in taking up a role under Koeman is Alfred Schreuder, who has also signed a deal until 30 June, 2022.
Schreuder and Larsson join Koeman's coaching staff 💪🔵🔴— FC Barcelona (@FCBarcelona) August 21, 2020
Schreuder was appointed head coach of Hoffenheim last March, having previously worked as Julian Nagelsmann's assistant, but he was sacked in June.
The former Feyenoord midfielder was assistant to Erik ten Hag at Ajax in 2018-2019 as the Eredivisie side reached the UEFa Champions League semi-finals with a series of sparkling performances.