A steel-concrete composite beam is composed of a steel beam and concrete slap connected with shear connectors. Composite beams are highly efficient structural members in order to load carrying capacity because the tension component of the force pair originating from bending is carried by the steel profile and the compressive component is carried by the concrete slab in composite beams. In this study, numerical and experimental analysis of steel-concrete composite and strengthened steel-concrete composite beams is presented. In experimental study, one strengthened and one un-strengthened specimens are produced and tested in bending. Strengthening is produced applying carbon fiber reinforced polymers sheet to the lower flange of the steel beam and using steel fiber reinforced concrete in the concrete slab. Specimens are tested under four-point loading test. During the tests, load, deflection and strain values are collected by data acquisition system. In numerical study, the finite element models of the steel-concrete composite beams are generated and analyzed by Atena-GiD program. Comparison and evaluations are made in terms of strength, applicability, stiffness and energy consumption about the steel-concrete composite beams with carbon fiber reinforced polymers and steel fibered concrete for both numerical and experimental results.