Andreas Allescher (6 June 1828, Munich – 10 April 1903, Munich) was a German schoolteacher and mycologist.
Following training at the teachers' seminar in Freising, he spent several years teaching classes in Haag an der Amper, Munich and Engedey (near Berchtesgaden).
In 1862 he returned to Munich, where he spent many years as a teacher at several facilities, including a post as an instructor at the district teachers' seminar (from 1872).He made important contributions regarding fungi imperfecti to Rabenhorst's Kryptogamen-Flora series.
The mycological genera Allescheria, Allescheriella and Allescherina commemorate his name.