Alexandru A. Suțu (November 30, 1837–September 1919) was a Wallachian-born Romanian psychiatrist.
He was born in Bucharest into the aristocratic Soutzos family; his father Alexandru Sutzu was high vornic and cămăraș (official in charge of the royal court's pantry). His grandfather George Sutzu was high dragoman; George's brother was Prince Alexandros Soutzos. Suțu began school in his native country before entering the University of Athens, where he studied from 1856 to 1862 and obtained a doctorate in 1863. Unhappy with the education he received, he went to the medical faculty of the University of Paris, where he obtained a second doctorate in 1865, dealing with dyspepsia. He then returned home and began his activity as a physician. In early 1866, he was named secondary physician at Mărcuța Hospital in Bucharest, rising to chief physician in the summer of 1867 and thereafter director, remaining there until retiring.
At Mărcuța, he established a new type of specialized, clinical practice; he and his colleagues and disciples drew on a wide range of French, English and German models of psychological medicine, such as: Philippe Pinel and Jean-Étienne Dominique Esquirol's paradigm of mental alienation; John Conolly's doctrine of non-restraint; Jean-Pierre Falret's theory of the clinic; Bénédict Morel and Valentin Magnan's ideas on hereditary degeneracy; Charles Darwin's theory of evolution; and Wilhelm Griesinger's principle of the organic nature of mental illness.