Ba Commandery (巴郡) was a commandery of Yi Province in eastern Sichuan, stretching along the upper Yangtze and its tributaries. Together with neighbouring commanderies such as Baxi, it controlled the approaches between the Sichuan Basin and the middle Yangtze corridor.
In the late Eastern Han and Three Kingdoms periods Ba Commandery provided the background for several Shu officials and scholars. The learned official Qiao Zhou is associated in the sources with Xichong in Baxi and the wider Ba region, and campaigns in the Hanzhong–Baxi area often mention movements through Ba territory. Although the surviving histories focus more on neighbouring Baxi and Hanzhong as battlefields, Ba Commandery formed part of the strategic shield around Chengdu and the core of Shu Han’s eastern frontier.