A floor beam is a beam which is the direct support of the floor load of a building and transfers this load to the adjacent girders or columns is a floor beam or floor joist. These beams are commonly of steel, reinforced concrete, or wood. Prestressed, precast concrete is also used.

The term floor beam is also used to designate the transverse beams of the floor system of a bridge which transmit load to the longitudinal girders or trusses.