The observer-based finite-time passive control problem of a class of Lipschitz nonlinear systems with uncertainties and time delays is studied. The nonlinear parameters are considered to satisfy the global Lipschitz conditions and the exogenous disturbances are unknown but energy-bounded. By constructing an appropriate Lyapunov function, a observer-based state feedback controller is designed to guarantee that the resulting closed-loop system is finite-time bounded and satisfies the given passive constraint condition. Some sufficient conditions for the solution to this problem are derived in terms of linear matrix inequalities. Simulation results illustrate the validity of the proposed approach.