Nigel Pearson's men finished the season in some style at the King Power Stadium with Jamie Vardy celebrating his England call-up with the opening goal
Jamie Vardy marked his call-up to the England squad with a first-half goal, reacting first to Riyad Mahrez's parried effort after 16 minutes, applying a calm finish for his fifth goal of the season.
Matt Phillips came close for the visitors when he fired wide midway through the first half, but Marc Albrighton's fizzing drive just before the break doubled Leicester's lead.
Leonardo Ulloa added a third at the beginning of the second half by getting a touch to Wes Morgan's effort from close range, before Esteban Cambiasso produced a clinical finish a minute later.
Vardy's fellow England newcomer Charlie Austin headed home a consolation just before the hour in what could be his last appearance for the Londoners, with speculation continuing to surround the striker's future.
But Nigel Pearson's side dished out further punishment in the closing stages, with Andrej Kramaric netting as Leicester broke the 40-point mark in the Premier League for the first time since 2001.
An unchanged home side continued to dictate much of the early exchanges, but were nearly caught out when Joey Barton curled a speculative free-kick just over from distance on 11 minutes.
And Leicester took the lead four minutes later when Mahrez's shot was parried by Alex McCarthy straight into the path of an unmarked Vardy, who coolly slotted home.
Austin saw an effort well blocked by Robert Huth as QPR looked for a response, before Phillips fired marginally wide with a 25-yard drive after 36 minutes.
But the hosts ended the half two goals to the good when a bursting run into the box allowed Albrighton to latch onto Jeffrey Schlupp's cross and lash into the net.
Leicester continued their momentum after the break and extended their lead just five minutes into the second half when Ulloa produced a decisive touch to guide Morgan's goal-bound effort home.
The home faithful waited just 60 seconds for a fourth, as Cambiasso pounced on Richard Dunne's poor clearance to drill past the despairing McCarthy.
An Austin header from Barton's pinpoint cross provided a consolation for Ramsey's charges, but Leicester would go on to have the final say.
Vardy was substituted after 65 minutes to a standing ovation from the home faithful, but Leicester refused to rest on their laurels, with Cambiasso heading just wide after another Albrighton cross.
And Kramaric put the seal on a stunning end to the campaign for Leicester, latching onto Ulloa's flick-on before confidently finding the net to compound QPR's misery.
IN PICTURES The final day of the 2014-15 Premier League season