<p>Hole spins in silicon or germanium quantum dots have emerged as a capable platform for scalable solid-state quantum processors. In addition to benefiting from well-established manufacturing technologies, the large spin–orbit coupling of hole spin qubits enables fast control mediated by an electric field. Unfortunately, this coupling typically makes hole spin qubits susceptible to charge noise, which usually limits qubit coherence. Here we experimentally establish the existence of so-called sweet lines in the parameter space of field orientation where the qubit becomes insensitive to charge noise. We do this by varying the direction of a magnetic field applied to a silicon metal–oxide–semiconductor hole qubit. We also find that the observed sweet lines contain the points of maximal driving efficiency, in agreement with recent theoretical predictions. Furthermore, we show that moderate adjustments in gate voltages can substantially shift the sweet lines. This tunability allows several qubits to be simultaneously made insensitive to electrical noise, making it possible to design scalable qubit architectures that feature all-electrical spin control of many qubits.</p>