Otto Herman Swezey (7 June 1869 – 3 November 1959) was an American entomologist who was an expert on the insects of Hawaii, especially the Lepidoptera.
He described numerous species and many, like the psyllid genus Swezeyana, have been named in his honour by other entomologists.
Swezey was born in Rockford, Illinois to Adoniram Judson and Malinda Bruner.
He studied at Guilford Centre School House and received a BA from Lake Forest College, Illinois in 1896.
He investigated an outbreak of Perkinsiella saccharicida in Hawaii working with the Hawaiian sugar planters.