Otto Friedrich Karl Deiters (November 15, 1834 – December 5, 1863) was a German neuroanatomist. He was born in Bonn, studied at the University of Bonn, and spent most of his professional career in Bonn. He is remembered for his microscopic research of the brain and spinal cord.
Around 1860, Deiters provided the most comprehensive description of a nerve cell that was known to exist at the time. He identified the cells' axon, which he called an "axis cylinder", and its dendrites, which he referred to as protoplasmic processes. He postulated that dendrites must fuse to form a continuous network.
His name is lent to the "nucleus of Deiters", also called the lateral vestibular nucleus, and to "Deiters' cells", structures that are associated with outer hair cells in the cochlea of the inner ear. Deiters died in 1863 from typhoid fever at the age of 29. After his death, his work pertaining to nerve cells of the spinal cord was edited and published by anatomist Max Schultze (1825-1874).