With safety already assured after a remarkable run of form to end the season, the home fans were in raucous mood, and their team produced a vibrant display to ensure the party went with a swing.
Having been bottom for much of the season, Leicester made it 22 points from their last nine games and they finish the season in 14th place while QPR, whose relegation was sealed a fortnight ago, finished a disappointing campaign bottom of the standings.
After being greeted ecstatically by the home supporters, Leicester roared out of the blocks and Leonardo Ulloa curled an early shot just wide before Jeffrey Schlupp thumped an effort into the side netting.
And the hosts took the lead in the 16th minute when QPR goalkeeper Alex McCarthy fumbled a fairly weak Riyad Mahrez effort straight to Jamie Vardy, who gleefully marked his England call-up by firing home from close range.
QPR have struggled on their travels for most of the campaign and looked fairly impotent in the first half here, although Matty Phillips went close out of nowhere when he sent a long-range effort inches wide of the post.
But Leicester were soon threatening again and the lively Mahrez led a pacy counter-attack and then shot wide after a good challenge from Richard Dunne had denied Vardy.
The hosts were not kept at bay for long though and doubled their advantage two minutes before the interval, when Schlupp’s cross found its way to Marc Albrighton, who rifled a superb shot into the net from just inside the area.
QPR had a chance to get back into the game just after half-time but youngster Reece Grego-Cox volleyed wide from close range after a Phillips shot was deflected into his path.
And Leicester then scored twice in as many minutes to virtually wrap up the victory, with just under 40 minutes still to play.
There was an element of fortune about their third goal, Albrighton’s miscued effort falling nicely for Wes Morgan and his shot bouncing into the net off Ulloa (51), McCarthy getting a hand to the ball but proving unable to keep it out.
But there was nothing fortuitous about number four, which arrived moments later, Esteban Cambiasso thumping a beautiful shot into the corner of the net after controlling a Dunne clearance.
Like Vardy, Charlie Austin was named in the England squad this week, and he battled gamely in a losing cause, getting his reward when he produced a fine header from a Joey Barton free-kick to pull a goal back in the 57th-minute, his 17th of an excellent individual campaign.
And QPR could have had another later on, Nedum Onuoha heading a Barton corner wide from close range.
But the last half-hour was all about Leicester, who knocked the ball about with aplomb while the home fans made their appreciation clear, the clever Mahrez providing the highlights with some lovely bits of skill.
It looked like the hosts might have to settle for just the four goals but sub Andrej Kramaric got his name on the scoresheet with four minutes left.
QPR youngster Cole Kpekawa had just come on for his debut when a Schmeichel punt bounced off him and fell perfectly for Kramaric, who beat McCarthy with a powerful cross-shot.
Leicester and their fans can now look forward to a pleasant summer and they will be confident of posing teams plenty more problems next term, with players such as Vardy, Albrighton and Mahrez on hand.
QPR head back to the Championship and, with the contracts of several players due to expire and big money offers likely for Austin, it is probable they will field a much-different team when they begin life back in the second tier.
Leicester: Schmeichel (7), Huth (7), Morgan (7), Wasilewski (6), Cambiasso (8), King (6), Schlupp (7), Mahrez (8), Albrighton (8), Ulloa (7), Vardy (8)
Subs: De Laet (6), Drinkwater (6), Kramaric (7)
QPR: McCarthy (5), Onuoha (5), Dunne (6), Hill (6), Yun (5), Barton (5), Fer (5), Henry (5), Phillips (5), Grego-Cox (5), Austin (7)
Subs: Kpekawa (6), Comley (6)
Player of the match: Marc Albrighton