A9, previously known as Alice Nine (アリス九號.?, originally stylized as alicenine.), is a Japanese visual kei rock band formed in Tokyo in 2004. A9 was a part of PS Company until 2014. The band had King Records as its record label until 2010, when they joined Tokuma Japan. Then, in 2013, they joined Universal Music Group's Nayutawave Records.

The group has released six full-length records, some of which were distributed in Europe by CLJ Records, along with several EPs, singles, and DVDs. In 2015, they shortened their name to A9.