Conversations will now switch to who could replace the former Middlesbrough boss as manager of the English national team.
It is one of the most alluring seats in international football, but also one of the most intimidating.
The English FA will be hoping to replace Southgate with some urgency, even if on a short-term basis initially.
England are due to face Ireland in the opening match of their Nations League campaign on September 7th.
That said, let's take a look at a few stand-out names who could take over the Three Lions:
Graham Potter
Currently available and with Premier League experience under his belt, Graham Potter is likely to be the bookies' favourite to take over from Southgate.
The former Brighton and Chelsea boss could serve as an ideal replacement for England, if FA chiefs want to continue with a similar brand of football that got the Three Lions to two Euros finals.
It would perhaps be the safest bet for England, with the Nations League now on the horizon.
Though not a World Cup or a Euros title, it's an opportunity for England to 'put right' their shortcomings on the international stage.
With Potter, England could practically pick up where they left off under Southgate and take another run at silverware.
Eddie Howe
Not dissimilar to Potter, Eddie Howe possesses an even greater level of Premier League experience - but the Saudi-backed Newcastle boss is currently unavailable.
Managers can work for a nation and a club at the same time, but it's uncommon - and it would be especially bizarre to do so for a Premier League club and a competitive country.
That said, Newcastle underperformed last season and it has left Howe in an imperfect position at St James' Park.
The former Bournemouth boss has long since been linked with the England job and an offer from the FA could be too difficult to turn down.
A lot of uncertainty surrounds, but Howe is definitely a name that will be discussed by FA chiefs.
Pep Guardiola
Given his success in the Premier League, Manchester City boss Pep Guardiola has been talked about among England fans for a while as Southgate's potential successor.
Though, it remains to be seen if the Catalan will have the appetite to take on such a job when his reign at the Etihad Stadium ends.
Unlike the two managers mentioned before him, Guardiola has won major honours - and a lot of them.
A change could be good for England, with Southgate's 'safe' brand of football seemingly only able to get the Three Lions into finals - and not win them.
Guardiola has one year left on his contract with City and could fancy a new challenge next summer.
That said, England would be forced to wait and hire an interim manager for the upcoming Nations League.
It is at this point it's worth mentioning Lee Carsley, manager of England's U21s, as his name is almost certainly going to crop up in the coming weeks.
Jürgen Klopp
Emphasised by his recent Liverpool exit, Jürgen Klopp is another big name who England fans have been dreaming could take over after Southgate.
Quite the opposite to the former Boro man, Klopp's 'heavy metal' style of football would be a considerable shake-up for fans of the Three Lions.
Klopp, like Guardiola, has won many major honours in his career and the FA could see him as the man to finally deliver England their second trophy.
However, he is believed to be interested in one day taking over as manager of Germany and he may want to keep himself available should Julian Nagelsmann leave the job.
Additionally, Klopp isn't long out of the Liverpool hot-seat and previously said he was "running out of energy".
Sarina Wiegman
It would be difficult to create a shortlist of who could replace Southgate and not include a person who has managed to achieve more with the women's team than he has with the men's.
Sarina Wiegman has led England to two major finals - the Women's World Cup and Women's Euros - the latter of which was won by the Lionesses.
It remains to be seen if she would desire such a move, but it would make her the first woman in history to manage a men's national team.
That said, the English women's team are in the middle of Euro 2025 qualifiers and their upcoming match against Sweden could be pivotal.
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Wildcard shouts: Mauricio Pochettino, Thomas Tuchel, Gary O'Neil, Lee Carsley
