Judson Linsley Gressitt (16 June 1914 – 26 April 1982) was an American entomologist and naturalist who worked in Japan and China.

The family became refugees after the earthquake of 1923 and they moved to Oakland, California in 1925 where he recovered from pneumonia and typhoid.

Through his cousin E. Gorton Linsley, he became interested in insects and the outdoors as Boy Scouts where they were influenced by Brighton C. Cain.

In the 1950s he returned to work in Southeast Asia and took part in an expedition to study Metasequoia glyptostroboides, a living fossil in Sichuan.

[6][8] The species Paramelomys gressitti; the leaf-beetle genera Gressittella and Gressittana; and the horsefly genus Gressittia are named after him.