Electronic devices may be provided with compasses for detecting the Earth's magnetic field. Electronic devices may be provided with other electronic components. A compass may include a magnetic sensor and control circuitry configured to apply offsets or other compass calibration data to compass data to compensate for magnetic interference from the other electronic components. Other electronic components may include components such as cameras, auto-focus lens mechanisms, light sources, and displays. The control circuitry may be configured to apply compass calibration data that is specific to an electronic component and that is specific to an operational status of the component. The control circuitry may be configured to recognize a replacement electronic component and revert to an average compass calibration correction. The control circuitry may be configured to output interference-corrected compass data to applications running on the electronic device.