Disclosed is a flame-retardant polyamide resin composition, including: a polyamide (A) containing a diamine unit including 70 mol% or more of a p-xylylenediamine unit and a dicarboxylic acid unit including 70 mol% or more of a linear aliphatic dicarboxylic acid unit having 6 to 18 carbon atoms; an organic halogen compound (B) that serves as a flame retardant; an inorganic compound (C) that serves as a flame retardant aid; and an inorganic filler (D), in which the polyamide (A) includes a polyamide having a phosphorus atom concentration of 50 to 1,000 ppm and a YI value of 10 or less in a color difference test in accordance with JIS-K-7105, and a content of the organic halogen compound (B), a content of the inorganic compound (C), and a content of the inorganic filler (D) are 1 to 100 parts by mass, 0.5 to 50 parts by mass, and 0 to 100 parts by mass, respectively, with respect to 100 parts by mass of the polyamide (A).