Theorema is a genus of butterfly in the family Lycaenidae. The members (species) of this genus are found in the Neotropic ecozone.
Theorema is Latin for theorem, and a number of theorems are often or sometimes referred to by a Latin name in English, most notably two theorems of Carl Friedrich Gauss:
- Theorema Egregium, "Remarkable Theorem", best-known example
- Aureum Theorema, "Golden Theorem", better-known as quadratic reciprocity
- Theorema, a genus of butterfly