Nigel Pearson's side moved to the brink of securing their return to the top flight on Friday night with a 2-1 triumph over Sheffield Wednesday at the King Power Stadium.
That made it 21 Sky Bet Championship games unbeaten as they moved onto 89 points - two more than Cardiff won the division with last season - and meant they would be up if QPR lost at Bournemouth and Derby failed to beat Middlesbrough.
QPR went down 2-1 on manager Harry Redknapp's return to Dean Court, while the Rams suffered a 1-0 loss on Steve McClaren's return to the Riverside, meaning celebrations could begin in earnest for the Foxes.
Former Leicester and England striker Gary Lineker tweeted: "Leicester City are promoted to the Premier League. A sentence I've been waiting to say for 10 years."
Asked whether he would be watching the results come in on Saturday, Pearson replied bluntly on Friday evening: "No. My job is to get this club promoted. Whether it's tomorrow, whether it's Tuesday, the next week, the week after it's irrelevant really. It's about getting promotion."
But his players were clearly following events on Saturday afternoon, and once their promotion was confirmed, they were able to express their delight.
Goalkeeper Kasper Schmeichel said: "Achieving promotion was our aim but we want to win the league, no question of that. We've got six games left and we want to win the Championship.
"Tonight we celebrate but everyone who knows the mentality of the team or the coaching staff knows as soon as tonight's over we get back to work.
"We want to keep pushing on and we'll be back working hard ahead of Tuesday's game (at home to Brighton). The real hard work starts to stay in the Premier League."
And not satisfied with just having secured a top-two finish, forward Gary Taylor-Fletcher turned his attention to clinching the Championship title.
"We are premier league, say we are premier league!!! Get in. #promotionpush now becomes #champwinnerspush" he wrote.
Left-back Paul Konchesky posted: "Absolutely buzzing about the results today!! #wearegoingup #lcfc ! Let's enjoy the rest of season and go again in the top flight #comeon."
Midfielder Anthony Knockaert, whose stunning free-kick settled Leicester's win on Friday after Riyad Mahrez's third goal since joining from Le Havre in January had been cancelled out by Michail Antonio's solo effort in the first half, posted: "Leicester going up going up going up going up going up !!!!!!!!! I
LOVE LEICESTER YESSSSSSSSSSSSSSS."