Alton Downs may refer to:

• Alton Downs, Queensland, a locality in the Rockhampton Region, Queensland, Australia
• Alton Downs Station, a pastoral property in South Australia

• John Sinclair (song)
• John Sinclair (Umweltschuetzer)
• John Sinclair (Umweltschutzer)
• John's Incredible Pizza Co.
• John Singenberger
• John Singer
• John Singer (attorney)
• John Singer (disambiguation)
• John Singer (homeschooler)
• John Singer Sergeant
• John Singleton (baseball)
• John Singleton (disambiguation)
• John Singleton Millson
• John Sinker
• John S. Inman
• John Sinnott (politician)
• John sinrud
• John Sinrud
• John Siomos
• John Siptroth
• John Sirmond
• John Sisk Jr.
• John Sisko
• Johns Island (disambiguation)
• Johns Island (Nunavut)