Deformation of circular plates including clamped circular plate and simply supported circular plate induced by a sessile droplet is studied using linear, elastic, small-deflection theory for plate bending. In the theoretical analysis, it is assumed that the liquid-vapor interface has a thickness of 16 nm and liquid-vapor interfacial tension is uniformly distributed over a narrow area. Using superposition method, the theoretical solutions of the deflections of both plates are derived and agree well with the numeric solutions. Numerical simulation results show that when there is a sessile center-aligning droplet on the upper surface of the plates, the plates will bend downward and there are maximum deflections at the center of the wetted area, which are nearly proportional to gamma lva(3) sin theta/Eh(3). Moreover, 3D numerical simulations are made to discuss the effect of plate thickness on surface deformation and found that the surface deformation, decreases with increasing plate thickness. When the plate thickness exceeds the saturated value, it can be regarded as a plate with infinite thickness.