Joaquín María Argamasilla de la Cerda y Elío (Madrid, 4 April 1905 – 1985) was a Spanish noble who was the 11th Marquis de Santacara, but he is better known for claiming in the early 1920s a supposed ability to see through opaque objects.
Argamasilla convinced important people of the era such as Gustav Geley and Charles Richet of his powers, but he was exposed by Harry Houdini as a fraud in 1924.