Eusapia Palladino (alternative spelling: Paladino; 21 January 1854 – 16 May 1918) was an Italian spiritualist physical medium. She claimed extraordinary powers such as the ability to levitate tables, communicate with the dead through her spirit guide John King, and to produce other supernatural phenomena.

She convinced many persons of her powers, but was caught in deceptive trickery throughout her career. Magicians, including Harry Houdini, and skeptics who evaluated her claims concluded that none of her phenomena were genuine and that she was a clever trickster.

Her Warsaw séances at the turn of 1893–94 inspired several colorful scenes in the historical novel Pharaoh, which Bolesław Prus began writing in 1894.

Palladino was born into a peasant family in Minervino Murge, Italy. She received little, if any, formal education. Orphaned as a child, she was taken in as a nursemaid by a family in Naples. In her early life, she was married to a travelling conjuror and theatrical artist, Raphael Delgaiz, whose store she helped manage. Palladino later married a wine merchant, Francesco Niola.

Palladino visited Warsaw, Poland, on two occasions. Her first and longer visit was when she came at the importunities of the psychologist, Dr. Julian Ochorowicz, who hosted her from November 1893 to January 1894.

Regarding the phenomena demonstrated at Palladino's séances, Ochorowicz concluded against the spirit hypothesis and for a hypothesis that the phenomena were caused by a "fluidic action" and were performed at the expense of the medium's own powers and those of the other participants in the séances.

Ochorowicz introduced Palladino to the journalist and novelist Bolesław Prus, who attended a number of her séances, wrote about them in the press, and incorporated several Spiritualist-inspired scenes into his historical novel Pharaoh.

On 1 January 1894 Palladino called on Prus at his apartment. As described by Ochorowicz,