A foldable post for a shelving apparatus includes an upper post member, a lower post member, and a post joint for connecting the upper and lower post members end-to-end. The post joint includes an engaging tongue extended from an end portion of the first post wall of the upper post member, an engaging groove provided at an end portion of the first post wall of the lower post member, and a pivot hinge pivotally coupled the second post walls of the upper and lower post members, such that when the upper and lower post members are pivotally moved to engage the engaging tongue with the engaging groove, the upper and lower post members are interlocked and coupled with each other end-to-end.