Parnas may refer to:

• David Parnas (born 1941), pioneer of software engineering who developed the concept of module design which is the foundation of object-oriented programming today
• Jakub Karol Parnas (1884–1949), Polish biochemist
• Parnas, Saint Petersburg, historical region of Saint Petersburg
  • Parnas, Saint Petersburg Metro, metro station in Saint Petersburg
  • Parnas Railway Station, railway station in Saint Petersburg
• People's Freedom Party (abbreviated as PARNAS), an opposition political party in Russia
• Mount Parnassus, mountain in central Greece
• Mount Sutro (former name Parnassus), hill in San Francisco, California
• Parnassus, New Zealand, town in New Zealand
• Parnassos (municipality), municipality in Greece
• Parnas fountain, a fountain in Brno, Czech Republic

People's Freedom Party "For Russia without Lawlessness and Corruption" (, Partiya narodnoy svobody "Za Rossiyu bez proizvola i korruptsiyi", abbreviated as Parnas, Парнас) was a Russian liberal democratic political party founded on 13 December 2010 by opposition politicians Vladimir Ryzhkov, Boris Nemtsov, Mikhail Kasyanov and Vladimir Milov and de facto dissolved on 16 June 2012 (merged into RPR-PARNAS party). The name is a reference to the original liberal democratic Party of Popular Freedom.

Parnas may refer to:

• David Parnas (born 1941), pioneer of software engineering who developed the concept of module design which is the foundation of object-oriented programming today
• Jakub Karol Parnas (1884–1949), Polish biochemist
• Parnas, Saint Petersburg, historical region of Saint Petersburg
  • Parnas, Saint Petersburg Metro, metro station in Saint Petersburg
  • Parnas Railway Station, railway station in Saint Petersburg
• People's Freedom Party (abbreviated as PARNAS), an opposition political party in Russia
• Mount Parnassus, mountain in central Greece
• Mount Sutro (former name Parnassus), hill in San Francisco, California
• Parnassus, New Zealand, town in New Zealand
• Parnassos (municipality), municipality in Greece
• Parnas fountain, a fountain in Brno, Czech Republic

People's Freedom Party "For Russia without Lawlessness and Corruption" (, Partiya narodnoy svobody "Za Rossiyu bez proizvola i korruptsiyi", abbreviated as Parnas, Парнас) was a Russian liberal democratic political party founded on 13 December 2010 by opposition politicians Vladimir Ryzhkov, Boris Nemtsov, Mikhail Kasyanov and Vladimir Milov and de facto dissolved on 16 June 2012 (merged into RPR-PARNAS party). The name is a reference to the original liberal democratic Party of Popular Freedom.