Grease composition and rolling bearing

A grease composition comprising:

• a poly-α-olefin;
• a urea-based thickener;
• molybdenum dithiophosphate;
• and
• barium sulfonate, wherein
• a difference between an SP value of the urea-based thickener and an SP value of the poly-α-olefin is 3.5 or less,
• wherein the urea-based thickener is a urea-based thickener in which a ratio of an amount of an aliphatic amine to a total amount of an alicyclic amine and the aliphatic amine {amount of aliphatic amine:(total amount of alicyclic amine and aliphatic amine)} is 18:100 to 35:100 in molar ratio,
• wherein the alicyclic amine is selected from the group consisting of cyclohexylamine and dicyclohexylamine,
• wherein the aliphatic amine is octadecylamine,
• wherein a kinematic viscosity of the poly-α-olefin at 40° C. is 20 mm2/s to 40 mm2/s,
• wherein a content of the poly-α-olefin is 75% by mass to 85% by mass based on the grease composition, a content of the urea-based thickener is 8% by mass to 20% by mass based on the grease composition, a content of the molybdenum dithiophosphate is 0.05% by mass to 1.5% by mass based on the grease composition, and
• wherein a content of the barium sulfonate is 0.05% by mass to 1.5% by mass based on the grease composition.