  In this paper we consider Riemannian manifolds of dimension at least $3$,
with nonnegative Ricci curvature and Euclidean Volume Growth. For every open
bounded subset with smooth boundary we establish the validity of an optimal
Minkowski Inequality. We also characterise the equality case, provided the
domain is strictly outward minimising and strictly mean convex. Along with the
proof, we establish in full generality sharp monotonicity formulas, holding
along the level sets of $p$-capacitary potentials in $p$-nonparabolic manifolds
with nonnegative Ricci curvature.
