A foldable chair, including a first bracket and a second bracket that are hingedly fixed in an X-shape, and an adjusting mechanism connecting an upper portion of the first bracket and a lower portion of the second bracket. The adjusting mechanism includes a fixing member and a movable member, the fixing member including a slide groove, and the movable member including a limit member movable within the slide groove; the slide groove has a serrated first inner side wall and a smooth second inner side wall, and the limit member is snapable to the first inner side wall.