Liaison in general means:
- Communication between two or more groups.
- Co-operation, working together.
but may refer to:
- Affair, an unfaithful or adulterous sexual relationship
- Air Alliance, a Canadian Summit airline whose call sign was "Liaison'
- Collaboration, people working together
- Liaison aircraft, a small aircraft used by military forces
- Liaison Committee, a topical committee of the British House of Commons
- Liaison Committee (House of Lords), a select committee of the United Kingdom's House of Lords
- Liaison Committee on Medical Education
- Liaison (French), the pronunciation of a word-final consonant due to a following vowel sound in French
- Liaison job, a job that links two or more specialties
- Liaison (kitchen), a mix of 3 parts yolk and 1 part cream used by soups
- Liaison officer, a military officer who coordinates different forces or national units usually at staff level
- Liaison pilot, a World War II pilot who flew liaison aircraft
- Liaison psychiatry, psychiatry that specialises in the interface between medicine and psychiatry
- "Liaisons" (Desperate Housewives), an episode of the American drama series Desperate Housewives
- Liaisons (song), a song from the 1973 musical "A Little Night Music" by Stephen Sondheim
- "Liaisons" (Star Trek: The Next Generation), an episode of Star Trek: The Next Generation