Lek or LEK may refer to:
- Lek (biology), a type of animal territory in which males of a species gather
- Lek (currency), the currency of Albania
- Lek (pharmaceutical company), now part of Sandoz, the generic drug subsidiary of Novartis
- Lek (river), a river in the west of the Netherlands
- De Lek, a former manorial fiefdom in the Netherlands
- L.E.K. Consulting, international strategy consulting firm
- Tata Airport, Guinea (by IATA code)
- Lek, a fictional form of Cardassian currency in Star Trek
- Lek, the family nickname of King Bhumibol Adulyadej of Thailand