Provided is a polyolefin-based resin composition including a hydrogenated block copolymer (A) and a polyolefin-based resin (B), the hydrogenated block copolymer (A) being a hydrogenated product of a block copolymer including a polymer block (a) composed of a constitutional unit derived from an aromatic vinyl compound and a polymer block (b) containing 1 to 100% by mass of a constitutional unit (b1) derived from farnesene and 99 to 0% by mass of a constitutional unit (b2) derived from a conjugated diene other than farnesene; a mass ratio of the polymer block (a) and the polymer block (b) [(a)/(b)] being 1/99 to 55/45; 50 mol % or more of carbon-carbon double bonds in the polymer block (b) being hydrogenated; and a mass ratio of the polyolefin-based resin (B) and the hydrogenated block copolymer (A) [{polyolefin-based resin (B)}/{hydrogenated block copolymer (A)}] being 1/99 to 99/1. The polyolefin-based resin composition is favorable in flexibility and molding processability, excellent in weather resistance and whitening resistance, and also excellent in rigidity.