Eduard Oscar Schmidt (21 February 1823, in Torgau – 17 January 1886, in Kappelrodeck) was a German zoologist and phycologist.

He initially studied mathematics and science at Halle, then continued his education in Berlin, where he came under the influence of Christian Gottfried Ehrenberg and Johannes Peter Müller.

As far back as 1862 Oscar Schmidt showed that "cuttings" of sponges will attach themselves and grow.

[1][2] Schmidt built a reputation based upon a handbook of comparative anatomy, the 9th edition of which, by Arnold Lang, was issued under the title Lehrbuch der vergleichenden Anatomie der wirbellosen Tiere (1888–1894).

He made significant contributions to Brehms Tierleben, and was the author of several treatises on sponges.