Johannes Friedrich August von Esmarch (9 January 1823 – 23 February 1908) was a German surgeon. He developed the Esmarch bandage and founded the Deutscher Samariter-Verein, the predecessor of the Deutscher Samariter-Bund.
Esmarch was born in Tönning, Schleswig-Holstein. He studied at Kiel and Göttingen, and in 1846 became Bernhard Rudolf Konrad von Langenbeck's assistant at the Kiel surgical hospital. He served in the Schleswig-Holstein War of 1848 as junior surgeon, and this directed his attention to the subject of military surgery. He was taken prisoner, but afterwards exchanged, and was then appointed as surgeon to a field hospital. During the truce of 1849 he qualified as Privatdocent at Kiel, but on the fresh outbreak of war he returned to the troops and was promoted to the rank of senior surgeon.
In 1854 Esmarch became director of the surgical clinic at Kiel, and in 1857 head of the general hospital and professor at the University of Kiel. During the Schleswig-Holstein War of 1864, Esmarch rendered good service to the field hospitals of Flensburg, Sundewitt and Kiel. In 1866 he was called to Berlin as member of the hospital commission, and also to take the superintendence of the surgical work in the hospitals there. When the Franco-Prussian War broke out in 1870, he was appointed surgeon-general to the army, and afterwards consulting surgeon at the great military hospital near Berlin.
In 1872 Esmarch married Princess Caroline Christiane Auguste Emilie Henriette Elisabeth of Schleswig-Holstein-Sonderburg-Augustenburg (1833–1917), aunt of Empress Augusta Viktoria. In 1887 a patent of nobility was conferred on Esmarch. He died at Kiel.