Thomas Campbell Eyton JP, DL (10 September 1809 – 25 October 1880) was an English naturalist whose fields were cattle, fishes and birds.

He studied at St John's College, Cambridge,[2] where he was a contemporary and friend of Charles Darwin.

Besides Darwin, Eyton enjoyed some correspondence with other naturalists including Louis Agassiz, Asa Gray, and Alfred Russel Wallace.

A collection of letters sent to Eyton are held at the Cadbury Research Library, University of Birmingham.

This archive collection also contains the correspondence of his father-in-law, Robert Aglionby Slaney, and other family members.