Liaison 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