A magnetic field sensor circuit with common-mode voltage nulling, reduces or eliminates the effect of common-mode variation and transients due to rotation of the magnetic field sensor terminals between the bias current source and sensor output voltage terminals. A switching circuit rotates the bias current source and sensor output voltage terminals between pairs of terminals of the semiconductor magnetic field sensor. After each rotation, the switching circuit momentarily shorts all of the terminals of the semiconductor magnetic field sensor to a reference voltage such as ground. After a predetermined period of time, a sample/hold circuit having an input coupled to the sensor output terminals samples and holds the voltage at the sensor output voltage terminals, resulting in a sampled output free of common mode error between samples due to common-mode error and magnitude changes between magnetic field sensor terminal pairs.