The title mol-ecule, C(14)H(9)NO(2), is nearly planar with a dihedral angle of 3.72 (4)° beteewn the plane of the phenyl ring and the 3,1-benzoxazin-4-one fragment. The mol-ecules are arranged into stacks parallel to the b axis via π-π stacking inter-actions [centroid-centroid distance = 4.2789 (11) Å] and the crystal packing is additionally stabilized by weak inter-molecular C-H⋯O inter-actions.