ALK or Alk may refer to:
Airlines ALK Airlines, a Bulgarian charter airline Alaska Air Group (stock ticker symbol ALK) SriLankan Airlines (ICAO code ALK)
Places Alk, Albania, a village Alk, Iran, a village in Kurdistan Province Alk-e Kohneh ("Old Alk"), a village in Kurdistan Province, Iran Aslockton railway station, Nottinghamshire, England (National Rail code ALK)
Biology and medicine Anaplastic lymphoma kinase, a human gene Alk-, a root word used in organic chemistry ALK or ALK-Abelló, a Danish pharmaceutical company Automated lamellar keratoplasty, a type of eye surgery
Vessels , a German cargo ship in service 1928–45 A sailing ship renamed as Albatross
See also ALK1-7, an activin receptor-like kinase protein e.g. ALK1