Rudolf Arndt (31 March 1835 – 29 January 1900) was a German psychiatrist from Bialken, district of Marienwerder.
Arndt studied in Greifswald and Halle, preferably under Felix von Niemeyer (1820 – 1871), Heinrich Adolf von Bardeleben (1819 – 1895), and Heinrich Philipp August Damerow (1798 – 1866), and was conferred doctor of medicine on 20 February 1860. From 1861 he had private practice, but also participated in the campaigns of 1864, 1866, and 1870 – 1871. It was a time when no German surgeon needed to suffer from want of work and study material. He was habilitated in 1867 was appointed professor of psychiatry at Greifswald in 1873. He died of angina pectoris.