A polycarbonate-based resin composition, including: a polycarbonate-based resin satisfying requirements (1) and (2); and a styrene-based resin blended into the polycarbonate-based resin, wherein a ratio of the polycarbonate-based resin in 100 mass % of a total amount of the polycarbonate-based resin and the styrene-based resin is from 50 mass % or more to 99 mass % or less: (1) the polycarbonate-based resin contains a polycarbonate-polyorganosiloxane copolymer containing a polycarbonate block formed of a specific repeating unit and a polyorganosiloxane block containing a specific repeating unit, and an aromatic polycarbonate-based resin except the polycarbonate-polyorganosiloxane copolymer; and (2) the polycarbonate-based resin has a structure in which a domain containing the polyorganosiloxane block is present in a matrix containing the aromatic polycarbonate-based resin as a main component, and a domain containing at least one selected from a block derived from the aromatic polycarbonate-based resin and the polycarbonate block is present inside the domain.