Supermassive black holes and their host galaxies grow together over time, producing correlations between the black hole mass and various galaxy properties. Determining the evolution of these correlations requires precise measurements of the masses of distant black holes. We observed the gravitationally lensed quiescent galaxy MRG-M0138 at redshift 1.95 using James Webb Space Telescope integral field spectroscopy to spatially resolve the kinematics of stars within the black hole's sphere of influence. By using a foreground lens model and fitting stellar dynamical models, we determined the mass of its inactive black hole to be [Formula: see text] solar masses. Comparing this measurement to local galaxies, we found that [Formula: see text] is higher than expected given the galaxy's bulge mass but consistent with the correlation of [Formula: see text] with stellar velocity dispersion.