A lubricating oil composition for internal combustion engines of passenger and commercial four-wheeled vehicles is provided which can exhibit excellent fuel efficiency performance and wear resistance reliability. The lubricating oil composition includes a base oil and a complex polyester mixture. The base oil includes at least one of poly-α-olefin, an ester-based base oil, or a partially hydrogenated mineral oil. The complex polyester mixture includes a polyester obtained by condensing a polyhydric alcohol, a polycarboxylic acid, and a monohydric alcohol having an oxyalkylene group. The content of the complex polyester mixture is 0.01% by mass or more with respect to the total mass of the lubricating oil composition, the high-temperature shear viscosity (HTHS viscosity) at 150° C. is 1.0 mPa·s to 2.6 mPa·s, and the NOACK evaporation amount is 40% or less.