To provide a lubricating oil supply device for an internal combustion engine, including a lubricating oil pump at one end of a balancer shaft while eliminating the need for providing an oil path in the balancer shaft.

A suction oil path 48 for guiding lubricating oil to the lubricating oil pump 25 and a discharge oil path 49 for guiding the lubricating oil compressed by the lubricating oil pump 25 to an in-shaft oil path 53 are provided in the thickness of a crank case 11. Thus, the lubricating oil supply device for the internal combustion engine 10 includes the lubricating oil pump 25 at one end of the balancer shaft 14 while eliminating the need for providing the oil path in the balancer shaft 14.