An innovative and reliable electrochemical sensor was proposed for simple, sensitive and selective determination of F⁻ ions. The sensor based on the fabrication of porous and electroactive Fe-based metal organic frameworks [MIL-101(Fe)]. It was blended with graphite powder and liquid paraffin oil to from carbon paste electrode (CPE). The MIL-101(Fe)@CPE was characterized using different techniques such as scanning electron microscope, powder X-ray diffraction spectroscopy, Fourier transform infrared spectroscopy, energy dispersive X-ray, cyclic voltammetry, electrochemical impedance spectroscopy, differential pulse voltammetry. The MIL-101(Fe)@CPE exhibited two redox peaks (anodic and cathodic) corresponding to Fe³⁺ and Fe²⁺, respectively. The determination of F⁻ ions based on the formation of a stable fluoroferric complex with Fe³⁺/ Fe²⁺, decreasing the currents of redox species. It was found that the anodic peak current (Ipa) is linearly proportional to the concentration of F⁻ in the range of 0.67–130 μM with a limit of detection (S/N = 3) of 0.201 μM. The electrode exhibited good selectivity towards F^- detection with no significant interferences from common anions. The as-fabricated sensor was applied for the determination of F⁻ in environmental water samples with recoveries % and RSDs % in the range of 98.1%–102.4% and 2.4%–3.7%, respectively.