James Vance May (1873–1947) was an American psychiatrist and an early proponent for and classification of mental diseases. He was among the first to recognize mental disease as a public health problem, a view that did not gain recognition and acceptance for many years. May contributed numerous research articles to the scholarly literature. He spoke German and nearly completed a German-English dictionary of psychiatric terms. He translated a book on schizophrenia by the German psychiatrist Karl Wilmanns. May died in 1947.