  We find the gravity dual of $\mathcal{N}=2^*$ super-Yang-Mills theory on
$S^4$ and use holography to calculate the universal contribution to the
corresponding $S^4$ free energy at large $N$ and large 't Hooft coupling. Our
result matches the expression previously computed using supersymmetric
localization in the field theory. This match represents a non-trivial precision
test of holography in a non-conformal, Euclidean signature setting.
