Maurice Rapport (23 September 1919 – 18 August 2011) was a biochemist who is best known for his work with the neurotransmitter serotonin. Rapport, Irvine H. Page, and Arda A. Green worked together to isolate and name the chemical. Alone, Rapport identified its structure and published his findings in 1948. Research since its discovery has implicated serotonin with mood regulation, appetite, sexual drive, and sleep as well as gastrointestinal roles. After his work with serotonin, Rapport did important research with cancer, cardiovascular disease, connective-tissue disease and demyelinating diseases.