Formulas
- Charles Loewner
- Chebyshev function
- Chebyshev rational functions
- Cheeger constant (graph theory)
- Chemistry
- Chen Jingrun
- Chern class
- Chinese remainder theorem
- Choi's theorem on completely positive maps
- Chordal graph
- Albanese variety
- Albert algebra
- Albertson conjecture
- Alcuin's sequence
- Aleksandrov–Clark measure