An object of the present invention is to provide an aqueous developer for a flexographic printing plate, which has excellent concentration suitability and good storage stability in a case of being made into a concentrated solution, an aqueous developing concentrated solution for a flexographic printing plate, and a manufacturing method of a flexographic printing plate using these. The aqueous developer for a flexographic printing plate of the present invention is an aqueous developer for a flexographic printing plate including an anionic surfactant, a nonionic surfactant, and water, in which the anionic surfactant is a compound represented by Formula (1). R1—X1  (1) Here, in Formula (1), R1 represents an alkyl group having 3 to 20 carbon atoms, an alkenyl group having 3 to 20 carbon atoms, or an alkynyl group having 3 to 20 carbon atoms, which may have a substituent, and X1 represents a carboxylic acid group or a salt of the carboxylic acid group, a sulfonic acid group or a salt of the sulfonic acid group, a sulfate group or a salt of the sulfate group, or a phosphoric acid group or a salt of the phosphoric acid group.