August Neilreich (12 December 1803, Vienna 1 June 1871) was an Austrian lawyer and botanist.
He studied law at the University of Vienna, eventually attaining the position of Oberlandesgericht Rath. At the age of 53 he was forced into early retirement from the legal profession due to illness.
As a young man, he was inspired by the botanical work of Ludwig Ritter von Köchel (1800-1877). Although he is largely known for investigations of flora native to Vienna and Lower Austria, he published works on plants found throughout the Austrian Empire.
The plant genus Neilreichia was named in his honour by Eduard Fenzl (1808–1879). His name is also associated with the species Asperula neilreichii (Eastern Alps-Meier).[1]