AC1

AC1 may refer to:

• AC1, a ranking grading within the Royal Air Force between 1919 and 1964
• AC1, a candidate phylum of bacteria
• AC¹, a complexity class in circuit complexity
• AC1 Sentinel, an Australian cruiser tank
• AC-1, an IEC Utilization Category
• Action Comics #1, containing the first appearances of several superheroes
• Atlantic Crossing 1, an optical submarine telecommunications cable system
• Assassin's Creed, the first game in the Assassin's Creed series