This paper presents a Complementary Loaded Split Ring Resonator (CLSRR) based compact, wideband, waveguide bandpass filter. Three identical CLSRRs were fabricated and placed on the transverse plane of a standard WR-90 waveguide at a quarter wavelength distance to form the filter. The proposed filter was initially simulated using Ansoft HFSS (version 14) and then fabricated and measured. The measured result shows a fractional bandwidth of 18.80% at 10.05 GHz. Total length of the filter is only 20.33 mm which is compact enough. Detailed design procedure has been presented along with the equivalent circuit of the filter. A table has been provided to compare the performance of the proposed filter with those already available in the literatures. The table shows that the proposed filter is compact and has higher bandwidth, lower insertion loss and higher return loss.