Second order conformally superintegrable systems generalise second-order (properly) superintegrable systems. They have been classified, essentially, in dimensions two and (partially) three only. For properly superintegrable systems, a foundation for an algebraic-geometric classification in arbitrary dimension has recently been developed by the authors. The present paper extends this geometric framework to conformally superintegrable systems.Using a rigorously geometric approach, we obtain a set of simple and universal algebraic equations that govern the classification of (the conformal equivalence classes of) second-order conformally superintegrable systems for dimensions three and higher. This sheds new light on the conformal geometry underpinning second-order conformally superintegrable systems. We demonstrate that conformal superintegrability is a conformally invariant concept, on a conformal manifold.For properly superintegrable systems on constant curvature spaces, we show that Stäckel equivalent systems are conformally equivalent with the conformal rescaling given by powers of eigenfunctions of the Laplacian. Invariantly, their equivalence is characterized by a shared density of weight 2. On the n-sphere the conformal scale function satisfies a Laplace eigenvalue equation with quantum number n + 1.