HMM
- Central Mashan Miao language
- Filler (linguistics)
- HMM (company)
- Hail Mary Mallon
- Hammerton railway station
- Hatch Mott MacDonald
- Heavy meromyosin
- Heavy metal music
- Heroes of Might and Magic
- Heterogeneous memory management
- Hidden Markov model
- Homenmen
- Homenmen (disambiguation)
- Hum (sound)
- Interjection
- Zoids