- The second letter of the Greek alphabet.
- (IPA) voiced bilabial fricative.
- (chemistry) Used in chemical nomenclature to refer to the second of several isomers, positions or variations.
- β-carotene is the most well-known isomer of tetraterpene hydrocarbons, C40H56.
- (topology) Stone–Čech compactification
- (physics) beta ray, beta particle, beta radiation
- Lower-case beta (βήτα), the second letter of the ancient Greek alphabet. It represented the voiced bilabial plosive: /b/. It is preceded by α and followed by γ.
- Lower-case beta (βήτα), the second letter of the modern Greek alphabet. It represents the voiced labiodental fricative: /v/. It is preceded by α and followed by γ.
See also beta