Football fans have united in praise of the English underdogs, who claimed the title despite starting as 5000/1 outsiders. Theories abound about the side's incredible winning streak.
Was it a team blessing by a buddhist monk, sent by the club's Thai owner Vichai Srivaddhanaprabha, that helped seal Leicester City's fortunes as winner of the English Premier League?
Or was it good luck brought on by the city's connection to a Middle Ages-era English King, Richard III, which gave the side a remarkable boost this season? Richard's remains were reburied last year, just 1.6 kilometers (1 mile) from the club's ground, and just as the club's fortunes started to turn around.
Those are just two of the theories that are doing the rounds following the "Foxes" spectacular achievement, which was confirmed on Monday evening when Spurs held London rivals Chelsea to a 2-all draw.
A draw with United wasn't enough on the weekend, but Chelsea secured the championship on Leicester's behalf
The reaction to Leicester's title win led to a massive spike in traffic to social media from the UK.
Fans and big names from the world of football, politics and showbusiness took to social media and the club's website to share their joy that a club whose squad cost just 69 million euros ($80 million) to assemble, a pittance compared to the league's big four clubs, could win the league.
FIFA president Gianni Infantino described the team's success as a "fairytale", while Real Madrid's winger Gareth Bale, tweeted "Gutted for @SpursOfficial but congrats to @LCFC, amazing season!! Love Football."
Ex-Leicester and England striker Gary Lineker said: "Leicester City have won the Premier League. The biggest sporting shock of my lifetime, and it's only my team."
Chelsea skipper John Terry said: "To do what they've done this year has been unbelievable and given hope to the smaller teams."
Grammy and Oscar-winning singer Adele, tweeted: "Leicester... What an inspiration, the best f***** story ever! Congratulations!!!! X"
Meanwhile British Prime Minister David Cameron also sent his praise.
Former Leicester and Wales midfielder Robbie Savage perhaps best summed up the historic moment when he tweeted: "An unbelievable night for Leicester. This is the greatest achievement in British sport. I was a massive skeptic of (Leicester manager) Claudio Ranieri but he proved me so wrong."
On Monday evening, Ranieri flew back from a brief trip to Italy, where he had met his 96-year-old mother for lunch, to watch the title-deciding match in the UK. In comments posted on the teams website, he said "I'm so proud," paying tribute to his players' "determination" and "spirit." "I never expected this when I arrived."
Leicester players gathered at the home of striker Jamie Vardy to watch the Spurs vs Chelsea match. The party erupted when the final whistle was blown and Foxes win became clear.
Outside Leicester City's stadium, thousands of fans gathered during the night for an impromptu celebration.
Later, fans circled the city centre blaring their car horns, while others warned that European giants such as Barcelona were next in their sights as Leicester prepare to enter the Champions League for the first time.
"We're coming for you, (Lionel) Messi!" shouted Chris Whiting, 20, in a reference to Barcelona's star Argentine forward.
At the beginning of the season, bookmakers Labrokes offered odds of 5,000/1 on Leicester winning the title. On Monday, the company faced a record payout of 31 million euros ($37 million), despite persuading some fans to cash out of the bet early, and pledged never to repeat the offer.
Leicester's win completely overshadowed Monday's World Snooker Championships title match, which was won by a Leicester-born player just a few minutes after the premier league title was confirmed.
"To be Premier League champions is a fantastic achievement and I want to say well done to Claudio and the boys," Mark Selby tweeted, shortly after his own win.
Leicester will be presented with the Premier League trophy following their final home game of the season against Everton on Saturday.