A ceiling system in one embodiment includes an overhead support grid comprised of a plurality of intersecting grid support members and a ceiling tile mountable to the grid. Retaining clips support the ceiling tile from the grid which may be concealed from view. The retaining clips each include a cavity that receives a grid support member and a pair of resilient mounting elements configured to locking! y engage a support member. The mounting elements are laterally movable in response to inserting the support member into the cavity of the retaining clip. In one embodiment, the movable elements include locking tabs which create a snap-fit interlock with the grid support, member for securing the ceiling tile to the grid.