A reduced order cyclic method was developed to compute limit-cycle oscillations for large, nonlinear, multidisciplinary systems of equations. Method efficacy was demonstrated for two simplified models: a typical-section airfoil with nonlinear structural coupling and a nonlinear panel in high-speed flow. The cyclic method was verified to maintain second-order temporal accuracy, yield converged limit cycles in about 10 Newton iterates, and provide precise estimates of cycle frequency. This method was projected onto a low-order space using a set of variables governing the amplitudes of empirically derived modes, which were computed with the proper orthogonal decomposition. In this reduced order form, the cyclic Jacobian was greatly compressed, allowing accurate limit cycle solutions to be very efficiently computed. Nomenclature s = Time step normalized by period t = Time step x = Panel node spacing γ = Ratio of specific heats λ = Reduced velocity (airfoil); pressure parameter (panel) µ = Mass ratio = Mode matrix ν = Poisson's ratio, 0.3 M ∞ = Freestream Mach number N f = Number of variables N m = Number of modes N t = Number of time intervals in oscillation N x = Number of nodes on panel (excluding end points) p = Pressure T = Oscillation period w = Panel deflection v = Panel velocity, ∂w/∂t