Lemma may refer to:
- Lemma (mathematics), a proven statement used as a stepping-stone toward the proof of another statement
- Lemma (morphology), the canonical form or citation form of a word
- Lemma (psycholinguistics), an intermediate form a word about to be uttered takes during speech production
- Lemma (logic), which is simultaneously a premise for a contention above it and a contention for premises below it