Oswald Seeliger (14 May 1858 in Biala – 17 May 1908 in Leipzig) was a German zoologist, known for his studies involving the anatomy and developmental history of tunicates.
From 1877 he studied natural sciences at the universities of Leipzig, Jena and Vienna, receiving his doctorate from the latter institution in 1882.
He took a study trip to southern France, Spain and North Africa, and from 1883 conducted research at the zoological station in Trieste.
In 1886, he obtained his habilitation for zoology and comparative anatomy at the University of Berlin, and from 1898 to 1908 was a full professor at the University of Rostock.
[1] He was a younger brother of astronomer Hugo von Seeliger (1849–1924).