| C1 | Protolude |
| CallStack | Protolude.Base, Protolude |
| callStack | Protolude.Base, Protolude |
| cancel | Protolude |
| cancelWith | Protolude |
| cast | Protolude |
| castWith | Protolude |
| catch | Protolude |
| catchE | Protolude |
| catchError | Protolude |
| catches | Protolude |
| catchJust | Protolude |
| catchSTM | Protolude |
| catMaybes | Protolude |
| ceiling | Protolude.Base, Protolude |
| Chan | Protolude |
| Char | Protolude.Base, Protolude |
| check | Protolude |
| chr | Protolude |
| cis | Protolude |
| clearBit | Protolude |
| CmpNat | Protolude.Base, Protolude |
| coerceWith | Protolude |
| Coercible | Protolude.Base, Protolude |
| Coercion | |
| 1 (Data Constructor) | Protolude |
| 2 (Type/Class) | Protolude |
| Comp1 | Protolude |
| CompactionFailed | |
| 1 (Data Constructor) | Protolude |
| 2 (Type/Class) | Protolude |
| compare | Protolude |
| comparing | Protolude |
| complement | Protolude |
| complementBit | Protolude |
| Complex | Protolude |
| concat | Protolude |
| concatMap | Protolude |
| concatMapM | Protolude.Monad, Protolude |
| Concurrently | |
| 1 (Type/Class) | Protolude |
| 2 (Data Constructor) | Protolude |
| concurrently | Protolude |
| conFixity | Protolude |
| conIsRecord | Protolude |
| conjugate | Protolude |
| conName | Protolude |
| Const | |
| 1 (Data Constructor) | Protolude |
| 2 (Type/Class) | Protolude |
| const | Protolude |
| Constraint | Protolude.Base, Protolude |
| Constructor | Protolude |
| cos | Protolude.Base, Protolude |
| cosh | Protolude.Base, Protolude |
| countLeadingZeros | Protolude |
| countTrailingZeros | Protolude |
| currentCallStack | Protolude.Base, Protolude |
| curry | Protolude |
| cycle | Protolude |
| cycle1 | Protolude |