Mariano de la Paz Graëlls y de la Aguera (1809 – 1898) was a Spanish entomologist notable for pioneering work on the insects of corpses.
Graëlls was born in Tricio, in the Province of Logroño. He died in Madrid where he had been Professor of Zoology.
The Graellsia genus of moths and the Graells's tamarin are named after him. He also identified the Iberian subspecies (Meles meles marianensis) of the badger.