Abstract We report a magnetostrictive composite–fiber Bragg grating (MC–FBG) magnetic field sensor based on the direct coupling of the magnetostrictive strain in an epoxy-bonded Terfenol-D particle pseudo-1–3 MC actuator with a FBG strain sensor. The MC–FBG sensor exhibits a large and fairly linear quasistatic peak wavelength shift of 0.68 nm under an applied magnetic field of 146 kA/m and a wide extrinsic magneto-optical signal frequency range up to at least 60 kHz. These quasistatic and dynamic characteristics, together with the electromagnetic interference immunity, large-scale multiplexing potential and self-reference capability, enable the application of the MC–FBG sensor in distributed magnetic field sensing over long distances.