He scored 46 goals in 216 appearances for Arsenal and, after retiring in 2014, the Sweden winger spent a season coaching Arsenal's Under-15 side.
Following a short spell as Wolfsburg assistant manager, Ljungberg returns to the Emirates Stadium after Arsene Wenger ended his 22-year reign as Arsenal manager at the end of the season. Wenger has been replaced by Spaniard Unai Emery.
“I'm delighted to be returning to the club. Arsenal has always been a special place for me and I'm really excited at this opportunity to work with our under-23 team,” Ljungberg said on Tuesday. “I look forward to working with the talented young players we have at the club.
“I know many of them well and will work hard to help them continue developing and become the best players and people they can be.”
Ljungberg played a prominent role in Arsenal's Premier League and FA Cup double triumph of 2002 and was part of the 'Invincibles' team which went unbeaten for the 2004 league campaign.
Ljungberg, who also played for West Ham, Seattle Sounders, Chicago Fire and Celtic, joined Wolfsburg as former Arsenal Academy manager Andries Jonker's assistant in 2017.
But he left when Jonker was sacked as manager of the German side after just seven months in charge. Arsenal's new Academy chief Per Mertesacker said: “It's great to have Freddie back at the club.
“He understands the club's values and how important it is to give young players the opportunity to grow and develop.”
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