Abstract This paper, a compact low-pass filter (LPF) with an Elliptic function response using P-shaped resonators is presented. The LPF with simple structure results in the low insertion loss less than 0.1 dB and high return loss better than 20 dB, in the pass-band. The proposed filter with a −3 dB cutoff frequency of 2.61 GHz is fabricated and measured. The measured results show that the proposed LPF has significant advantages such as a wide stop-band from 2.9 GHz to 17.3 GHz with the suppression level better than −20 dB, and it has an acceptable sharp frequency response in the transition band. The measurement results are in good agreement with the simulation results.