Global navigation satellite system(GNSS) receivers are highly susceptible to continuous wave(CW)interference because the received signals are extremely weak. Current interference mitigation techniques mainly use a notch filter or transform domain. This paper proposes a computationally effective algorithm based on a frequency-locked loop(FLL) to mitigate interference in GNSS receivers. The performance of the algorithm is validated through an analysis of the characteristics of the interference reduction filter and interference estimation precision. A Monte Carlo simulation is used to compare the proposed algorithm with various previous algorithms:the adaptive IIR notch filter, adaptive linear-phase FIR filter, and N-sigma DFT algorithm. The simulation results show that the proposed algorithm exhibits excellent interference estimation precision and superior antijamming performance compared with the conventional algorithms. Current interference mitigation techniques mainly use a notch filter or transform domain. This paper proposes a computationally effective algorithm based on a frequency -locked loop (FLL) to mitigate interference in GNSS receivers. The performance of the algorithm is validated through an analysis of the characteristics of the interference reduction filter and interference estimation precision. A Monte Carlo simulation is used to compare the proposed algorithm with various previous algorithms: the adaptive IIR notch filter, adaptive linear-phase FIR filter, and N-sigma DFT algorithm. The simulation results show that the proposed algorithm exhibits excellent interference estimation precision and superior antijamming performance compared with the conventional algorithms.