We demonstrate a novel magnetometer that utilizes the Langevin nonlinear magnetization of superparamagnetic nanoparticles as the sensing medium. The magnetic sensor exploits the even-order harmonics of the magnetization response, particularly the second harmonic, which is proportional to the local magnetic field component. By remotely detecting the magnetization response, the magnetometer enables non-invasive, localized, and distributed magnetic field sensing without requiring wired connections, with a small sensing volume, which can be used for in situ biomedical sensing, geomagnetic monitoring, smart diagnostics, and distributed industrial sensing. In the linear operating regime, the magnetometer provides a measurement range of ± 0.2 mT and a high sensitivity of 10 pT/√Hz, while an extended operating mode allows measurements over a range exceeding ± 0.5 mT. The sensor offers a dynamic bandwidth from dc up to a few kilohertz, determined by the excitation frequency.