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