Diphenylamine is mainly used as antioxidant of synthetic rubber, fuel and pharmaceutical intermediate, antioxidant of lubricating oil and stabilizer of gunpowder.

Verification of nitrate, chlorate and other oxidizing substances. Catalytic determination of iridium. Spectrophotometric Determination of nitrate. Redox indicator. Haploid breeding medium. Making dyes. It is a stabilizer for nitrocellulose, explosives and firewool.