3,4-Dihydroxybenzaldehyde, also known as protocatechuic aldehyde, is an organic compound with the chemical formula C7H6O3. It is a white to light yellow crystalline solid and is commonly used as an intermediate in the synthesis of pharmaceuticals, dyes, and perfumes. Additionally, it is utilized as a flavoring agent in the food industry and serves as an antioxidant with potential health benefits.