A novel fourth-order Colpitts chaotic oscillator is presented. Theoretic design and circuit implementation shows that the fourth-order Colpitts chaotic oscillator can be obtained by parallelizing a capacitor C3 with inductor L in a canonical third-order Colpitts chaotic oscillator. The resonance frequency is changed by adjusting the value of C3, and the oscillator becomes chaotic through doubling period bifurcation. The dynamical behaviors of the fourth-order Colpitts chaotic oscillator are further investigated, including equilibrium points, bifurcations and Lyapunov exponents. Finally, this approach is verified in both numerical simulations and circuit experiments.