Since Alex Ferguson stepped down in 2013, the 20-times English champions have not won the league title despite some big names such as Louis van Gaal and Jose Mourinho taking the reins.
The following are some of the candidates among the favourites to replace Ten Hag:
RUUD VAN NISTELROOY
The former United forward was a crowd favourite during his time at the club where he scored 150 goals and is no stranger to the dugout having taken the role of assistant coach this season.
Van Nistelrooy will replace Ten Hag on an interim basis but this is not his first big job as a coach. The Dutchman managed PSV Eindhoven in 2022-23 when he guided them to the Dutch Cup and second place in the Eredivisie.
United will hope the squad responds to a former player taking charge in the manner that Van Nistelrooy's ex-teammate Ole Gunnar Solskjaer revived the club's fortunes when he came in on an interim basis and was rewarded with the permanent role.
XAVI HERNANDEZ
After a stellar career in which he won 25 trophies as a midfielder with Barcelona, Xavi cut his teeth in management in Qatar where he led Al-Sadd to a league title and several cups before he was brought back to the Catalan club in November 2021.
In his first full season, Barca romped home in the LaLiga title race with four games to spare despite the club's deep financial crisis as they ended a four-year drought and he brought some much-needed stability.
The club were in the doldrums following the departure of talisman Lionel Messi but Xavi managed to turn things around with a squad that had a rich mix of experience and youth before he was sacked earlier this year after a season of turmoil.
Xavi's confidence in developing academy products may work in favour of United, who have prided themselves in having youth players consistently breaking into the first team in the past.
GARETH SOUTHGATE
The former England boss has put his feet up since he resigned after the Euros final defeat in July and, although he failed to win a trophy, he did what many managers failed to do by reaching showpiece matches with a squad rich in talent.
After England's golden generation faltered in major tournaments, Southgate's young squad erased painful memories and gave the nation hope by going deep in tournaments -- including a World Cup semi-final and runners-up spot at the last two Euros.
Although criticised for being too pragmatic at times, Southgate's approach may be what United need after several managers have failed to leave their mark on a team which has no real tactical identity to speak of.
THOMAS FRANK
The Danish coach guided Brentford to the Premier League for the first time in 2021 and has since kept them competitive in the top flight with an attractive style of play and even managed a top-10 finish in the 2022-23 season.
His achievements despite the Bees' financial shortcomings and poor luck with injuries and suspensions have earned praise from managers such as Manchester City's Pep Guardiola, who said it was only a "question of time" before Frank managed a big European club.
Frank, however, has said he enjoys the freedom he has at Brentford where his style of management is aligned with the club's leadership and culture so the United project would have to appeal to him if he is to make the switch.
"Things can happen and you can want new inspiration, maybe you find another inspiration at your club and you stay," Frank told the Sports Agents podcast last week when he was linked with the United job.
"For sure, if I ever got the offer to go to a big club and I decided to go there, it would probably not make my life better. I think we all know that. Maybe it is a challenge you need to try."
KIERAN MCKENNA
As Ipswich Town soared to dizzying heights in two seasons as they secured back-to-back promotions to go from the third division to the Premier League this year, manager Kieran McKenna suddenly became hot property in English soccer.
The 38-year-old was linked with Brighton & Hove Albion, who have rarely got a managerial appointment wrong in recent years, as well as Chelsea before the Northern Irishman extended his stay at Ipswich ahead of the 2023-24 campaign.
McKenna has previously managed United's Under-18 side before he became an assistant manager at Old Trafford until his departure in December 2021 when he took on the challenge at Ipswich who were 12th in League One (third tier) at the time.
But following Ipswich's stellar rise, they are yet to win a Premier League game after nine rounds, sitting in the relegation zone with four points despite spending over 100 million pounds ($129.89 million) on new signings.
Nevertheless, McKenna's tactical approach with a high press was a breath of fresh air and could rejuvenate a United side who have often looked disorganised without any clear structure and rarely threatened to score many goals under Ten Hag.
One stumbling block for United to overcome would be that McKenna's Ipswich contract runs until 2028.
