To provide a method for producing various kinds of o- aminobenzenesulfonamide compounds in good yield from an easily available raw material.

The method for producing the o-aminobenzenesulfonamide compound represented by general formula (I) comprises the following steps (1) to (4): (1) a step for introducing a protective group to the amino group of a compound represented by general formula (II); (2) a step for halogenating the sulfo group of the compound obtained in the step (1); (3) a step for forming a sulfonamide by using the sulfonyl chloride obtained at the step (2) and a primary amine; and (4) a step for deprotecting the compound obtained at the step (3) to synthesize the compound represented by general formula (I). (In the formulas, R1 is a substituted or unsubstituted alkyl group or aryl group; R2 is a substituent; n is an integer of 0-4; when n is ≥2, two or more R2s are the same or different, and may form a ring by bonding to each other).