HLB may refer to:
- Halbi language of central India (ISO 639-3 language code: HLB)
- Helium light band, unit of surface flatness
- Help library, a VMS help file
- Herbst LaZar Bell, Inc., American product development company
- Hillsborough Resources, Canadian coal-mining company (Toronto Stock Exchange symbol: HLB)
- HLB International, international network of accountancy firms
- H.L. Boulton, Venezuelan import and export company
- Huanglongbing, disease of citrus fruits
- Hydrophilic-lipophilic balance, parameter used to classify surfactants according to their degree of hydrophilicity