Nepean may refer to:

• Division of Nepean, former federal electorate in New South Wales
• Electoral district of Nepean, state electoral district in Victoria, Australia
• Electoral district of Nepean (New South Wales), former state electoral district in New South Wales
• Nepean (federal electoral district), a Canadian electoral district covering Nepean and other parts of western Ottawa
  • Nepean—Carleton (federal electoral district), former Canadian electoral district (1979 to 1988, 1997 to 2015)
  • Nepean—Carleton (provincial electoral district), former Canadian electoral district (1999 to 2014)

• Nepean College of Advanced Education, a former higher education institution in Western Sydney, Australia
• Nepean Creative and Performing Arts High School, Sydney, Australia
• Nepean Hospital, Kingswood, New South Wales, Australia
• Nepean Observatory, an observatory, part of Western Sydney University at Werrington North, New South Wales
• UWS Nepean, a former campus of Western Sydney University

• Nepean (surname), several people with the surname
• Nepean baronets, a baronetcy created in Dorset, England, UK

• Nepean Bay, a bay in South Australia
  • Nepean Bay Conservation Park, a protected area in South Australia,
  • Nepean Bay, South Australia, a locality
• Nepean Highway, Victoria
• Nepean Island (Norfolk Island)
• Nepean Island, Queensland
• Nepean River, NSW
• Point Nepean, Victoria

Ontario

• Kìwekì Point, a hill overlooking the Ottawa River in Ottawa, Ontario, formerly known as Nepean Point
• Nepean, Ontario
• Nepean Bay (Canada), on the Ottawa River, Ontario
• Nepean Township, Ontario

British Columbia

• Nepean Sound, British Columbia

• Hawkesbury and Nepean Wars (1794–1816), a series of conflicts between British forces and Indigenous clans in the area west of Sydney
• Nepean Sea Road, Mumbai, India
• Nepean Stars F.C., a football club in Sierra Leone