Abstract: The present invention provides a lubricating oil composition comprising: a lubricating base oil; 1.0% by mass or more and 15.0% by mass or less of a dispersant poly(meth)acrylate compound having the weight average molecular weight of 20000 or more and 200000 or less; 0.05% by mass or more and 6.0% by mass or less of a thiadiazole compound; 1.5% by mass or more and 4.0% by mass or less of a polysulfide compound; and 0.2% by mass or more and 1.5% by mass or less of a friction modifier, based on the total amount of the lubricating oil composition, wherein the mass ratio of the polysulfide compound content to the thiadiazole compound content (polysulfide compound/thiadiazole compound) is 0.4 or more and 50 or less, and the kinematic viscosity at 100° C. of the lubricating oil composition is 7.0 mm2/s or more and 35.0 mm2/s or less.