A stackable tool box assembly is provided with first and second tool boxes, each of which has side latches with catches. The first and second tool boxes have a stacked orientation in which the second tool box sits on top of the first tool box, and in which the catch edge of the catch of the latch of the second tool box engages a lip of the first tool box to hold the first and second tool boxes together. The first and second tool boxes have a released orientation from the stacked orientation in which the catch edge of the catch of the latch of the second tool box is pivoted to disengage from the lip of the first tool box so that the first and second tool boxes are released from each other.