Napoleon Nikodem Cybulski (Polish pronunciation: [napɔˈlɛɔn t͡sɨˈbulski]; 14 September 1854 – 26 April 1919) was a Polish physiologist and a pioneer of endocrinology and electroencephalography. In 1895, he isolated and identified adrenaline. He is also known for conducting one of the first EEG recordings of the cerebral cortex. He was nominated for the Nobel Prize in Physiology or Medicine three times between 1911–1918.