- ACLU stands for American Civil Liberties Union
- ACLU stands for Anti-Christian Litigation Unit
- ACLU stands for American College of Life Underwriters (now American College; insurance)
- ACLU stands for Afghan Construction & Logistics Unit
- ACLU stands for Adult and Community Learning Unit (UK)
- ACLU stands for Adventurous Cowboys Living Underwater (Prairie Home Companion)
ACLU