August Hjalmar Edgren (October 18, 1840 – December 9, 1903) was a Swedish-American linguist, professor, and author.
August Hjalmar Edgren was born in Östanås, Älvsbacka parish in Värmland, Sweden. He was the son of Axel Edgren (1813–1864) and Mathilda Berger (1817–1878). He was educated in Karlstad and . He was a graduate of the University of Uppsala and the royal military school of Sweden. Edgren passed the officer's exam in Stockholm in 1860, and subsequently served during the American Civil War in the Union Army, where he entered the 99th New York Regiment as 2d lieutenant in January 1862. He was promoted to 1st lieutenant, and in August 1863 he was assigned to the engineer corps. He resigned towards the end of 1863, went back to Sweden and took commission in the Värmland Regiment, in which he served from February 1864 until August 1870, having been adjutant from July 1869. In the beginning of the 1870s Edgren returned to the United States, where he studied at Cornell University and Yale University.
Hjalmar Edgren divided his professional career between Sweden and the United States. He was a teacher of languages in Riverview Academy in 1871/2, instructor in French, German, and Sanskrit in Yale from 1874 until 1880, and lecturer in Sanskrit in the University of Lund, Sweden, from 1880 until 1884, when he became professor of modern languages and Sanskrit at the University of Nebraska. Edgren served as the Rector of the University of Gothenburg from 1891–93.
In 1896, Edgren was one of the professors who organized the graduate college at the University of Nebraska–Lincoln. The graduate college at University of Nebraska was the first graduate school in the trans-Mississippi West. At the University of Nebraska, Edgren served as a professor of romance languages and comparative philology. He added courses in Scandinavian languages to the romance language department.