Abstract: A keyed paint container holder for paint mixers having a pivoting interlock key movable with respect to a paint container receptacle of the holder for orienting a rectangular footprint paint container to have a handle of the paint container in a corner of the holder adjacent the interlock key. The interlock key has first and second portions and is pivotable with respect to the holder to at least first and second positions and, optionally, to a third position. The holder accepts a cylindrical paint container as an alternative to the rectangular footprint paint container.