The former Arsenal midfielder played more than 200 matches for the Gunners and won the Premier League twice in a nine-year spell at the club from 1998.
Following a short stint as assistant manager at Wolfsburg, the former Sweden international will formally return to Arsenal next month.
“I’m delighted to be returning to the club,” Ljungberg, 41, said. “Arsenal has always been a special place for me and I’m really excited at this opportunity to work with our under-23 team.
“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 joyed Arsenal from Halmstad in 1998, and played a prominent role in the north London side’s Premier League and FA Cup double triumph of 2002. He was also part of the Invincibles team which went unbeaten for the 2004 league campaign.
The midfielder left Arsenal in 2007 before brief spells at West Ham, Seattle Sounders, Chicago Fire and Celtic. He hung up his boots in 2012.
Ljungberg, who also played 75 times for Sweden, previously coached the Arsenal Under-15 and Under-19 squads.
He moved to Wolfsburg as former Arsenal Academy manager Andries Jonker’s number two, but left when Jonker was sacked by the German side after just seven months in charge.
Arsenal’s new Academy manager Per Mertesacker said: “It’s great to have Freddie back at the club. He brings great footballing experience and the highest possible levels of enthusiasm, energy and encouragement for our young professionals.
“He understands the club’s values and how important it is to give young players the opportunity to grow and develop.
“When Freddie left for Wolfsburg it was with the club’s blessing and with a return to Arsenal some day in mind.
“Everyone knows Freddie loves the club and we look forward to him developing his career with us.”
Fifty-four managers were dismissed in the English professional game in the 2017/18 season, the second-highest total ever.
Data published on Monday by the League Managers Association also showed that the managers relieved of their duties last term had an average tenure of 1.18 years – a slight improvement on 2016/17 (1.16 years) but still the second-lowest average in the six seasons for which data was published.
The 15 managers sacked in the Premier League was the highest total on record going back to 2005/06, beating the mark of 12 from 2013/14 and 2015/16.
That included two apiece at West Brom and Swansea as both clubs suffered relegation while of the 20 clubs in the 2017/18 Premier League, only half will begin the new season under the same manager.
Thirteen managers lost their jobs at Championship level, 16 in League One and 10 in League Two.
The LMA said the average tenure of all current managers was 1.53 years and listed Paul Tisdale as the longest-serving manager in the professional game at 11.94 years, following Arsene Wenger’s resignation from Arsenal.
The study, though, ran only up to May 31 – Tisdale quit his post as Exeter boss the following day to leave Jim Bentley, who had reached just over seven years at Morecambe by the end of May, as the longest serving.
The average tenure of Premier League managers come the end of the season was slightly higher at 1.70 years, with the Championship and League One languishing at 1.10 and 1.22 respectively.
The League Two average – boosted by Tisdale, Bentley and the now second-placed Gareth Ainsworth at Wycombe – was highest at 2.12 years.
The 24-year-old striker’s agreement commits him to Spurs until 2024 and follows manager Mauricio Pochettino extending his own deal until 2023.
Kane’s decision to stay put comes as a welcome boost for Spurs, who made the announcement with footage of their new stadium.
Tottenham are due to return to White Hart Lane next season, after a season as tenants at Wembley.
“I’m really excited, it’s a proud day,” Kane said on tottenhamhotspur.com.
“Obviously it’s been a great few seasons and I’m looking forward to the future.
“I’m looking forward to the new stadium first and foremost and just to keep progressing as a club.
“For us as a club, it’s just about keeping improving and we’ll work hard to do that.”
Kane scored 30 goals in the recently completed Premier League season, when Spurs finished third, and finished with a total of 41 goals in all competitions. He has passed 20 goals in each of the last four seasons.