Jamie Vardy, Erik Lamela and Harry Kane all hit braces as Spurs came out on top 5-4 in the final-day showdown, with the latter player ending the season on 30 Premier League goals for the first time in his career as a result.
The hosts maintained a brief period of pressure after drawing level, during which Toby Alderweireld tried his luck from 20 yards out, but the defender's effort was straight at Eldin Jakupovic in the Leicester goal.
The Foxes edged their noses back in front moments later after Walker-Peters failed to hold off Vardy in the penalty area, allowing the striker to square a pass towards the onrushing Mahrez, who blazed the ball over the line from close range to make it 2-1 to the visitors.
Tottenham's best chance to equalise in the first half came in the 22nd minute when Jakupovic was forced into action to keep out Eric Dier's dipping header, moments before Lucas drove a follow-up effort narrowly wide.
Leicester almost claimed a third with the half-hour approaching as a Vardy-led counter ended with Demarai Gray shooting first time, forcing Spurs goalkeeper Hugo Lloris to get down quickly for the save.
The second half began in explosive fashion as Kelechi Iheanacho produced a contender for goal of the game just minutes in, claiming possession in the final third and curling an unstoppable strike into the top corner.
Despite going 3-1 down, Spurs' resolve remained strong and they registered an immediate response through Lamela, who was on hand inside the box to turn Walker-Peters's low cross over the line from close range.
Just four minutes later, the hosts were level thanks to a Christian Fuchs own goal, the Leicester defender deflecting the ball past his own goalkeeper after Lamela unleashed a screamer from the edge of the box.
Tottenham found themselves in front for the first time all afternoon on the hour mark when Lamela completed his brace, once again demonstrating poacher instincts to prod another Walker-Peters cross over the line.
The end-to-end action continued and Lloris was forced into another save in the 65th minute, going to ground to parry Iheanacho's powerful strike after Mahrez had picked out the Nigerian with a deft pass.
Vardy joined Lamela on two strikes for the afternoon in the 73rd minute, capping off a Mahrez-led counter by rifling the ball into the roof of the net, beyond the onrushing Lloris.
Tottenham's winner and Kane's 30th of the season came in the 76th minute when Danny Rose picked out his teammate in the box, and he smashed home what proved to be the winning goal from 12 yards out.
The England international's finish was the last piece of goalmouth action of any note on a chaotic afternoon at Wembley, which Spurs will now vacate to move into their revamped White Hart Lane for next season.
The result sees Tottenham secure a third successive top-three finish in the Premier League, while defeat for Leicester means they remain in ninth place.
TOTTENHAM (4-2-3-1): Lloris; Walker-Peters, Alderweireld, Vertonghen, Rose; Sissoko (Son 84'), Dier; Lucas (Alli 74'), Eriksen, Lamela (Sanchez 78'); Kane
LEICESTER (4-2-3-1): Jakupovic; Simpson (Choudhury 56'), Morgan, Maguire, Fuchs; Silva, Iborra; Mahrez, Iheanacho (Barnes 85'), Gray (Diabate 61'); Vardy