Caspar Maximilian Brosius (12 June 1825 – 17 February 1910) was a German physician and psychiatrist born in Burgsteinfurt, Westphalia.
Following graduation, he practiced medicine in Burgsteinfurt, and in 1855 started work as an assistant to Adolph Albrecht Erlenmeyer (1822-1877) at the Asyl für Gehirn- und Nervenkranke in Bendorf bei Koblenz.
At Bendorf he strove in providing living conditions for the mentally ill that were the equivalent to those of the healthy, non-institutionalized public.
He believed that his patients should have a place where they "felt at home", and deemed it necessary to assess and treat them on an individual basis.
In 1860 he published a translation of John Conolly's "Treatment of the insane without mechanical restraints" as Die Behandlung der Irren ohne mechanischen Zwang.