This article presents a composite right–left-handed (CLRH) zeroth-order resonator designed on a ferrite substrate. Numerical modelling and measurements of the device are presented. The proposed structure is realized in coplanar waveguide configuration using an interdigital capacitor and a shortcircuited stub inductor to add the left-handed property to the resonator. The ferrite substrate is magnetized in a direction perpendicular to the propagation direction. The tunable nature of the proposed device can be achieved by changing the applied magnetic bias. The resonator is designed to be tuned over the 3–5 GHz frequency band. Measured insertion loss is 5 dB giving interesting perspectives for the device. The length of the proposed device is 5.2 mm, which can be considered very small compared with a traditional half wave resonator.