- ACII stands for Assassin’s Creed 2 (video game)
- ACII stands for Affective Computing and Intelligent Interaction (conference)
- ACII stands for Associate of the Chartered Insurance Institute
- ACII stands for Allergy and Clinical Immunology International
- ACII stands for Advanced Computer Innovations, Inc. (Pittsford, NY)
- ACII stands for Adjuvant-Carrageenan-Induced Inflammation
ACII