Lajos Méhelÿ (August 24, 1862 – February 4, 1953) was a Hungarian zoologist, herpetologist, professor, and author.

Besides his zoological work, he increasingly dedicated his life to Hungarian racial theory and Turanism.

He started elementary school in his birthplace and finished fourth grade in Kassa (today: Kosice, Slovakia).

From 1896 to 1915 he worked for the Department of Zoology in the Hungarian National Museum, where he was the director of the collection of mounted specimens for three years.

After the First World War he expanded his Darwinist approach to the human sciences and started dealing with racialist biology.