The class nine student died when mudslide buried four rooms of the Ex-Army High School near Pokhara, a popular tourist spot, while exams were underway, police said.
He was rushed to an area hospital, but could not be saved.
Among the injured were five teachers and eight students.
They were being treated at hospitals and their conditions were out of danger, said Superintendent of Police Hari Bahadur Pal.
Nepal Police, Army personnel and locals rescued several people and students from the site of the collapse.