2,6-Dihydroxybenzaldehyde, also known as gentisaldehyde, is a chemical compound with the molecular formula C7H6O3. It is a white to light yellow crystalline solid that is soluble in alcohol and ether. 2,6-Dihydroxybenzaldehyde is commonly used as an intermediate in the synthesis of pharmaceuticals, dyes, and perfumes due to its aromatic properties and chemical reactivity.