The Nobel Prize in Physiology or Medicine 1938 was awarded to Corneille Heymans "for the discovery of the role played by the sinus and aortic mechanisms in the regulation of respiration".

Corneille Heymans received his Nobel Prize one year later, in 1939. During the selection process in 1938, the Nobel Committee for Physiology or Medicine decided that none of the year's nominations met the criteria as outlined in the will of Alfred Nobel. According to the Nobel Foundation's statutes, the Nobel Prize can in such a case be reserved until the following year, and this statute was then applied. Corneille Heymans therefore received his Nobel Prize for 1938 one year later, in 1939.