We describe scalar and spinor fields on a noncommutative sphere starting fr
om canonical realizations of the enveloping algebra A=U(u(2)). The gauge ex
tension of a free spinor model, the Schwinger model on a noncommutative sph
ere, is defined and the model is quantized. The noncommutative version of t
he model contains only a finite number of dynamical modes and is nonperturb
atively UV regular. An exact expression for the chiral anomaly is found. In
the commutative limit the standard formula is recovered. (C) 2000 American
Institute of Physics. [S0022-2488(00)03905-0].