Spencer Fullerton Baird (1823–1887) was an American naturalist, ornithologist, ichthyologist and museum curator. Baird was the first curator to be named at the Smithsonian Institution. He would eventually serve as the second Secretary of the Smithsonian, from 1878 until 1887. He published over 1,000 works during his lifetime. He was dedicated to expanding the natural history collections of the Smithsonian and upon his death, had done so by expanding the collection from 6,000 specimens in 1850 to over 2 million upon his death.

Spencer Fullerton Baird (* 3. Februar 1823 in Reading, Pennsylvania; † 19. August 1887 in Woods Hole, Massachusetts) war ein US-amerikanischer Ornithologe und Ichthyologe.

Spencer Fullerton Baird est un ornithologue et un ichtyologiste américain, né le 3 février 1823 à Reading en Pennsylvanie et mort le 19 août 1887 à Woods Hole dans le Massachusetts.

Spencer Fullerton Baird, född 3 februari 1823 och död 19 augusti 1887, var en nordamerikansk zoolog.

Baird si laureò al Dickinson College di Carlisle, Pennsylvania, nel 1840. L'anno seguente organizzò un'escursione ornitologica attraverso le montagne della Pennsylvania, coprendo a piedi in ventuno giorni la distanza di 400 miglia (più di 640 chilometri), di cui 60 miglia (circa 96 km) solo l'ultimo giorno.