The state space approach is used to provide analytical solution for fundamental frequency analysis of functionally graded sandwich beams. The classical beam theory, first-order and higher-order shear deformation theories are employed to consider beams of various classical and non-classical boundary conditions. Governing equations of motions are derived from Hamilton's principle. The research investigates the effect of boundary conditions on the fundamental frequency with nine combinations of classical boundary conditions created from clamped, hinged, pinned and free conditions in accordance with three combinations of non-classical boundary conditions created from the assumption of an elastic support. In addition, the influence of material parameter and arrangement of layers as well as the slenderness ratio in vibration of functionally graded sandwich beams is examined.