Mount Parnassus is a mountain in Greece, sacred in mythology and a metaphor for the arts and learning.

Parnassus or Parnassos may also refer to:

• Parnassos (municipality), a former municipality in Phocis, Greece, named for Mount Parnassus
• Parnassus (Cappadocia), an ancient Roman town in Asia Minor, a former Catholic diocese and present titular see

• Parnassus, New Zealand, a town on the South Island

• Mount Parnassus (Colorado), a summit in the Rocky Mountains
• Mount Sutro, formerly Mount Parnassus, a hill in San Francisco, California
• Parnassus, Pennsylvania, a neighborhood of New Kensington, Pennsylvania

• Parnassus plays, a comedic cycle originally performed at Cambridge University 1598–1602
• Parnassos, a Greek literary magazine published by the Parnassos Literary Society in Athens, 1877–1895
• Parnassus (1973 magazine), an American literary magazine published in New York, 1973–2019
• Parnassus (Northern Essex Community College), the literary arts magazine of Northern Essex Community College, Massachusetts, founded in 1965

• Parnassus (Mantegna), a 1497 painting by Andrea Mantegna
• Parnassus (Poussin), a 1631–1633 painting by Nicolas Poussin
• The Parnassus, a 1511 painting by Raphael
• Frieze of Parnassus, an 1860s frieze on the Albert Memorial, London, England

• Parnassos, in myth, the son of the nymph Cleodora, and namesake of the mountain
• Parnassus (ship) – one of several vessels by that name
• Parnassos Strovolou, a Cypriot sports club in Strovolos

• Montparnasse, a neighbourhood in Paris
• Parnassia, a plant genus
• Parnassius, a butterfly genus
• Parnassianism, a 19th-century French literary movement
• The Imaginarium of Doctor Parnassus, a 2009 fantasy film