In this article, we study the decomposition into irreducible components of the fixed point locus under the action of \(\Gamma \) a finite subgroup of \(\textrm{SL}_2(\mathbb {C})\) of the smooth Nakajima quiver variety of the Jordan quiver. The quiver variety associated with the Jordan quiver is either isomorphic to the punctual Hilbert scheme of \(\mathbb {C}^2\) or to the Calogero-Moser space. We describe the irreducible components using quiver varieties over the McKay’s quiver associated with the finite subgroup \(\Gamma \) . We moreover give a general combinatorial model of the indexing set of these irreducible components in terms of certain elements of the root lattice of the affine Lie algebra associated with \(\Gamma \) . Finally, we prove that for every projective, symplectic resolution of a wreath product singularity, there exists an irreducible component of the fixed point locus of the punctual Hilbert scheme of the plane that is isomorphic to the resolution.