Baron Ernst von Feuchtersleben, fully Ernst Maria Johann Karl Freiherr von Feuchtersleben (April 29, 1806, Vienna – September 3, 1849, Vienna) was an Austrian physician, poet and philosopher.

He was born as a son of Ernst von Feuchtersleben (1765 - 1834). He was of an old Saxon noble family.

He attended the Theresian Academy in his native city, and in 1825 entered its university as a student of medicine. In 1833 he obtained the degree of doctor of medicine and settled in Vienna as a practicing surgeon. In 1834 he married. The young doctor kept up his connection with the university, where he lectured, and in 1844 was appointed dean of the faculty of medicine.

He cultivated the acquaintance of Franz Grillparzer, Heinrich Laube, and other intellectuals in Vienna. He interested himself greatly in educational matters, and in 1848, while refusing the presidency of the ministry of education, accepted the appointment of under secretary of state in that department. In this capacity he attempted to introduce some important reforms in the system of education, but, discouraged by the difficulties which he encountered, he resigned in December of the following year. His health gave way, and he died at Vienna on 3 September 1849.

Among his medical works may be mentioned: Über das hippokratische erste Buch von der Diät (Vienna, 1835) and Lehrbuch der ärztlichen Seelenkunde (1845). His poetical works include Gedichte (Stutt. 1836), among which is the well known beautiful hymn, which Mendelssohn set to music, Es ist bestimmt in Gottes Rat. As a philosopher he is best known by his Zur Diätetik der Seele ("Dietetics of the soul") (Vienna, 1838), which attained great popularity, and the tendency of which, in contrast to Hufeland's Makrobiotik ("On the Art of Prolonging Life"), is to show the true way of rendering life harmonious and lovely. This work had by 1906 gone into fifty editions. Noteworthy also is his Beiträge zur Literatur-, Kunst- und Lebenstheorie (Vienna, 1837 - 1841), and an anthology, Geist der deutschen Klassiker (Vienna, 1851; 3rd ed. 1865 - 1866). His collected works (with the exception of the purely medical ones) were published in 7 vols. by Fr. Hebbel (Vienna, 1851 - 1853). See M. Necker, "Ernst von Feuchtersleben, der Freund Grillparzers," in the Jahrbuch der Grillparzer Gesellschaft, vol. iii (Vienna, 1893).

According to the Encyclopædia Britannica Eleventh Edition, "He was a poet of fine aesthetical taste and a philosopher."