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