The present invention provides a combination chair including a plurality of chairs which can be separately used or can be combined together as one to be used. Each of the plurality of chairs comprises a seat portion supported by legs and a backrest provided on the seat portion. These chairs are designed so that the backrests thereof are jointed to be adjacent to each other by one side in the width direction when the seat portions of the chairs are stacked up in the up-and-down direction, and the lengths of the legs are set so that the lower ends thereof coincide when the chairs are combined together.
