The former England Under-21 boss was promoted to the top job at the end of September after predecessor Sam Allardyce was removed from the position after being caught up in a newspaper sting relating to alleged corruption in football.
Despite being increasingly tipped for the main role, Southgate had refused to talk up or deny the likelihood of becoming England's next manager permanently, instead constantly affirming he was focused only on helping his squad.
His demeanour had impressed the powers that be in the FA selection panel, however, and, after convening over the weekend for a penultimate meeting, English football's ruling body made Southgate's appointment permanent on Wednesday.
The news means the 46-year-old will oversee England's World Cup 2018 and Euro 2020 campaigns, with the former Middlesbrough boss revealing his pride at being appointed.
"I am extremely proud to be appointed England manager. However, I’m also conscious that getting the job is one thing, now I want to do the job successfully," he said in a statement on the FA's website.
"I’ve thoroughly enjoyed working with the players over these past four games and I think there’s huge potential. I’m determined to give everything I have to give the country a team that they’re proud of and one that they’re going to enjoy watching play and develop.
"For me, the hard work starts now."
FA chief executive Martin Glenn expressed his faith that Southgate is the right man for the task, stating: "We are delighted to confirm Gareth as England manager.
"He’s obviously somebody we know well but it’s his understanding of international football and the development set-up at St. George’s Park that is important.
"He performed extremely well during the four games he was in temporary charge and he impressed us during a tough interview process.
"Gareth is a great ambassador for what the FA stands for, he’s a very good football tactician and a leader but beneath that he’s a winner and that’s an important part of the job."
Southgate’s first match as permanent manager will come in March 2017 against Germany in a friendly, before they take on Lithuania in a World Cup qualifier.