2-Formylpyridine, also commonly called pyridine-2-carboxaldehyde, is an organic compound with the formula NC5H4CHO. It is one of three isomeric pyridinaldehydes. The other isomers are pyridine-3-carboxaldehyde and pyridine-4-carboxaldehyde. 2-Formylpyridine is a colorless oily liquid with a distinctive odor. Older samples are often brown-colored owing to impurities. It serves as a precursor to other compounds of interest in coordination chemistry and pharmaceuticals. Pyridine aldehydes are typically prepared by oxidation of the hydroxymethyl- or methylpyridines.