Johann Heinrich Blasius (October 7, 1809 – May 26, 1870) was a German zoologist. In 1836, he was appointed as a professor at the Collegium Carolinum in Braunschweig. In 1840, he founded the Botanischer Garten der Technischen Universität Braunschweig. In 1859 he was appointed as the director of the newly founded Naturhistorisches Museum (Braunschweig) and in 1866 also of the Herzog Anton Ulrich Museum.
He was the author of two books on vertebrates: Fauna der Wirbelthiere Deutschlands (1857), (Vertebrates of Europe), and Die wirbelthiere Europa's (1840) (with Alexander Keyserling).
His son, August Wilhelm Heinrich Blasius, was an ornithologist.