To provide a collapsible chair by which sitting comfortableness can be obtained and which can be formed to be excellent in design.

A front leg rod 10A and a rear leg rod 10B are connected to each other by an upper beam 14 and a lower beam 12 to form a right frame body 22 and a left frame body 24, a front oblique rod 16A and a rear oblique rod 16B obliquely extended downward from the upper beam 14 are rotatably fitted to the upper beam 14, the front oblique rod 16A and the rear oblique rod 16B are connected to each other by a locking beam 26, the locking beam 26 is provided with an engagement part which can be engaged and disengaged with and from the lower beam of the opposite frame body, and a collapsible support material 20 for supporting the body of one who is seated is fitted between the upper beams 14 of the right frame body 22 and the left frame body 24.