A piezoelectric resonator, in particular for a rotary piezoelectric motor, the resonator including a stationary base and an oscillating mass extending around a longitudinal axis, the oscillating mass being provided with at least one flyweight, preferably two opposing flyweights, wherein the resonator includes a flexible guide connecting the oscillating mass to the base, so as to be able to cause the oscillating mass to oscillate about a centre of rotation in a pendulum movement, the flexible guide comprising at least a first flexible blade connecting the base to the oscillating mass, the first flexible blade comprising at least in part an electrically actuatable piezoelectric material for deforming the first flexible blade and causing the oscillating mass to oscillate.