In this study, the forced vibration of a simply supported Euler-Bernoulli beam is investigated. Small-scale effects with a nonlocal parameter are taken into consideration in a nonlocal beam model. The vibration amplitude corresponding to local and nonlocal effects are analyzed under the simply supported boundary conditions. An amplitude ratio between the non-local and local responses is derived to observe the impact of the non-local parameter and excitation frequency on the dynamic behavior of the beam. The effect of modal number and nonlocal parameter on the forced vibration response is examined. The variation of amplitude ratio with frequency ratio for different values of modal number and non-local parameter are shown graphically.