Congo, Republic of the
18 years of age; universal
Cook Islands
18 years of age; universal (adult)
Costa Rica
18 years of age; universal and compulsory
Cote d'Ivoire
18 years of age; universal
Croatia
18 years of age; universal (16 years of age, if employed)
Cuba
16 years of age; universal
Cyprus
18 years of age; universal
Czech Republic
18 years of age; universal
Denmark
18 years of age; universal
Djibouti
18 years of age; universal