Andreas Heinrich Karl Brandt (23 May 1854, Schönebeck near Magdeburg – 7 January 1931, Kiel) was a German zoologist and marine biologist.
Following graduation he served as an assistant to Emil Du Bois-Reymond (1818–1896) at the physiological institute of the University of Berlin.
From 1882 to 1885 he worked at the zoological station in Naples, and in 1885 obtained his habilitation from the University of Königsberg under the direction of Carl Chun (1852–1914).
In 1922 Brandt became professor emeritus, and in 1924 was appointed chairman of the Preußischen wissenschaftlichen Kommission zur Untersuchung der deutschen Meere (Prussian Scientific Commission for the Investigation of German seas).
He is known for his research on the role that dissolved nitrogen and phosphorus compounds play upon oceanic life.