The 38-year-old was killed Saturday by the animal in Chitwan National Park, Nepal's biggest conservation area, located in the southern plains, police said.
Although attacks on humans are common as deforestation forces wildlife to stray into villages, rhinos rarely kill people, an expert said.
"Rhinos are not aggressive animals so it's rare for them to kill humans," the park's chief warden, Kamal Jung Kunwar, told AFP.
Kunwar said the rhino appeared to have killed the man because he had strayed into the animal's habitat in the park in the Himalayan nation.