A fiber-reinforced resin composition comprising: a polyamide resin; a polyolefin resin; and a reinforcing fiber, wherein a content of the polyamide resin and a content of the polyolefin resin are 7 mass% to 93 mass%, and 7 mass% to 93 mass%, respectively, with respect to a total of 100 mass% of the polyamide resin and the polyolefin resin, a content of the reinforcing fiber is 10 parts by mass to 200 parts by mass with respect to a total of 100 parts by mass of the polyamide resin and the polyolefin resin, an amount of the reinforcing fiber mixed with the polyamide resin is 75 mass% or more with respect to a total of 100 mass% of all reinforcing fibers blended into the composition, when one resin between the polyamide resin and the polyolefin resin is set as a first resin, and the other resin is set as a second resin, the composition has a bicontinuous structure including a bicontinuous phase having a continuous phase A consisting of the first resin and a continuous phase B consisting of the second resin and at least one dispersed phase of a dispersed phase a consisting of the second resin dispersed in the continuous phase A and a dispersed phase b consisting of the first resin dispersed in the continuous phase B, or a sea-island structure including a continuous phase C consisting of the first resin and a dispersed phase c consisting of the second resin dispersed in the continuous phase C, and in a resin phase separation cross-sectional structure observed under a microscope, a total of cross-sectional areas of dispersed phases having a cross-sectional area equal to or smaller than an average cross-sectional area of the reinforcing fiber is 20% or less with respect to a total of cross-sectional areas of all dispersed phases observed under the microscope. a polyamide resin; a polyolefin resin; and a reinforcing fiber, wherein a content of the polyamide resin and a content of the polyolefin resin are 7 mass% to 93 mass%, and 7 mass% to 93 mass%, respectively, with respect to a total of 100 mass% of the polyamide resin and the polyolefin resin, a content of the reinforcing fiber is 10 parts by mass to 200 parts by mass with respect to a total of 100 parts by mass of the polyamide resin and the polyolefin resin, an amount of the reinforcing fiber mixed with the polyamide resin is 75 mass% or more with respect to a total of 100 mass% of all reinforcing fibers blended into the composition, when one resin between the polyamide resin and the polyolefin resin is set as a first resin, and the other resin is set as a second resin, the composition has a bicontinuous structure including a bicontinuous phase having a continuous phase A consisting of the first resin and a continuous phase B consisting of the second resin and at least one dispersed phase of a dispersed phase a consisting of the second resin dispersed in the continuous phase A and a dispersed phase b consisting of the first resin dispersed in the continuous phase B, or a sea-island structure including a continuous phase C consisting of the first resin and a dispersed phase c consisting of the second resin dispersed in the continuous phase C, and in a resin phase separation cross-sectional structure observed under a microscope, a total of cross-sectional areas of dispersed phases having a cross-sectional area equal to or smaller than an average cross-sectional area of the reinforcing fiber is 20% or less with respect to a total of cross-sectional areas of all dispersed phases observed under the microscope.