A ceiling system, a ceiling panel, and a method of covering a ceiling support with a plurality of ceiling panels. In one aspect, the invention may be a ceiling system comprising: a plurality of ceiling panels, each of the ceiling panels comprising: an upper face; a lower face opposite the upper face; a first edge, a second edge, a third edge opposite the first edge, and a fourth edge opposite the second edge; each of the first and second edges comprising a tongue; and each of the third and fourth edges comprising a groove; and a plurality of alignment clips, each of the alignment clips comprising a cruciform rib element.