Ronald Ross may refer to:

• Ronald Ross (1857–1932), English physician and Nobel laureate; discoverer of the malaria parasite
• Sir Ronald Ross, 2nd Baronet (1888–1968), Irish politician; Ulster Unionist Northern Irish Member of Parliament
• Ronald Ross (shinty player) (born 1975), Scottish sportsman; shinty player for Kingussie
• Ronnie Ross (1933–1991), British jazz baritone saxophonist
• Ronald J. Ross, American radiologist

• Closterotomus ventralis
• Closter Plaza
• Closter Road-Oak Tree Road Historic District
• Closter (surname)
• Clostoeca
• Clostridial Cytotoxin family
• Clostridiales-2 RNA motif
• Clostridiales-3 RNA motif
• Clostridioides
• Clostridioides difficile
• Clostridioides difficile Infection
• Clostridium acetireducens
• Clostridium acidisoli
• Clostridium aciditolerans
• Clostridium acidotolerans
• Clostridium aestuarii
• Clostridium akagii
• Clostridium aldenense
• Clostridium aldrichii
• Clostridium algidicarnis
• Clostridium algidixylanolyticum
• Clostridium algifaecis
• Clostridium algoriphilum
• Clostridium alkalicellulosi
• Clostridium alkalicellum