Goals by Darwin Nunez, Bobby Clark and Diogo Jota in an eight-minute spell late in the first half gave the Reds a 3-0 lead at the interval.
Ben Doak then headed in their fourth midway through the second half to seal a thumping victory at the National Stadium.
With two weeks left before Liverpool kick off their Premier League season at Chelsea, manager Jurgen Klopp could reflect on a good day of preparation for his side.
"We had a lot of good moments but we can do better," said the German.
"I'm absolutely fine (with how things went). The result was good, nobody was injured – just a few knocks - and the atmosphere during and after the game was top-class. So yeah, it was a good day in the office."
Liverpool face Bayern Munich in another pre-season friendly in Singapore on Wednesday while Leicester, who were relegated from the Premier League last season, are returning to England for the start of their Championship campaign against Coventry City next Sunday.
Leicester had the first big opportunity after nine minutes when Kasey McAteer’s through ball found Wilfred Ndidi behind the Liverpool defence but the Nigerian midfielder’s attempt was smothered by goalkeeper Caoimhin Kelleher at point-blank range.
Liverpool were denied an opening goal shortly afterwards when Nunez's effort was ruled out for offside while Leicester goalkeeper Mads Hermansen did well to palm the ball away when Mohamed Salah attempted to find Jota with a low cross.
However, Liverpool's pressure would finally pay off on the half-hour mark. Hermansen kept out Jota's hard low shot from the left channel but he could only parry the ball to the far post where Nunez arrived to turn in for his side’s opening goal.
A second arrived five minutes later when Salah laid the ball off in the box for Clark with the 18-year-old sending a right-footed shot past Hermansen into the bottom corner of the net.
Salah also played a big part in Liverpool's third three minutes later as the Egyptian scooped the ball up for Jota to head the ball home.
Liverpool changed all 10 of their outfield players at half-time but they continued to enjoy the lion's share of possession in the second half.
They added a fourth in the 64th minute from a well-worked set piece as Joel Matip flicked Dominik Szoboszlai's corner to the far post for Doak to nod home.
Leicester went close to a consolation goal when Patson Daka's attempt was well blocked by Jarell Quansah while at the other end, Luis Diaz was twice left frustrated as he saw his headed goal disallowed for offside before being denied by a good save by Hermansen.
