Copp - Crim
- copperhead
- Coppertail
- coral pea
- Coral Sea
- Coral Sea Islands
- coral snake
- coral tree
- cordial
- corella
- corn
- corner a wave
- Corner, the
- cornstalk
- coronus
- correspondence school
- Corriedale
- corroboree
- cossie
- cottage
- cottonbush
- Council of Australian Food Technology Associations
- count-muster
- country
- Country Party of Australia
- country quota
- Country Women's Association
- county
- Court of Appeal
- Court of Petty Sessions
- Cousin Jack
- cowslip orchid
- CPI
- cracker
- Cracker night
- Cradle Mountain–Lake St Clair National Park
- crest-tailed marsupial mouse
- crested wattle
- crib-tin
