Nicotinic acid N-oxide is an organic compound with the formula (HO<sub>2</sub>C)C<sub>5</sub>H<sub>4</sub>NO. It is the amine oxide of nicotinic acid ((HO<sub>2</sub>C)C<sub>5</sub>H<sub>4</sub>N). It is prepared by oxidation of nicotinic acid or the hydrolysis of 3-cyanopyridine-N-oxide. The compound is a precursor to the popular drugs niflumic acid and pranoprofen.