An integrated fluxgate-induction sensor is formed of a combined fluxgate sensor and induction sensor using a common core. The sensor may be in serial operation where it switches between a fluxgate mode for measuring static magnetic fields and an induction mode for measuring alternating magnetic fields. Additionally, the sensor may be used in an interleaved operation where the sensor operates from the fluxgate mode during the transition period where its core is changing from a high permeability state to a low permeability state or vice versa, while the sensor operates in the induction mode when the core is in its high permeability state. The resulting sensor provides for a compact magnetic sensor system capable of sensing magnetic fields which oscillate from zero frequency to 10 kHz and higher.