Diener is a morgue worker responsible for handling, moving, and cleaning the corpse.

Diener may also refer to:

• Bertha Eckstein-Diener (1874–1948), née Diener, Austrian writer also known by her pseudonym Helen Diener
• Carl Diener (1862–1928), Austrian geographer, geologist and paleontologist
• Christian Diener (born 1993), German backstroke swimmer
• Drake Diener (born 1981), American professional basketball player
• Ed Diener (born 1946), American psychologist, professor and author
• Emil Diener, Swiss bobsledder
• Gottfried Diener (1926–2015), Swiss bobsledder
• James Diener, American music executive and entrepreneur
• Joan Diener (1930–2006), American theatre actress and singer
• John V. Diener(1887–1937), American politician
• Melanie Diener (born 1967), German operatic and concert soprano
• Theodor Otto Diener (1921–2023), American plant pathologist
• Travis Diener (born 1982), American professional basketball player
• Verena Diener (born 1949), Swiss politician

• Diener & Diener, an architectural firm established in Basel, Switzerland

• Marie Diener-West, American biostatistician and epidemiologist
• Robert Biswas-Diener (born 1972), American psychologist and author
• Deiner Córdoba (born 1992), Colombian footballer