August Wilhelm Heinrich Blasius (5 July 1845 – 31 May 1912) was a German ornithologist.
Blasius belonged to a family of scientists: his father was the ornithologist Johann Heinrich Blasius and his brother was the ornithologist Rudolf Heinrich Paul Blasius (1842-1907).
In 1870 he became the director of the Museum of Brunswick, and in the following year he became a professor of zoology and botany at the Technische Hochschule Herzogliche.