Spirocyclic indole derivatives are fascinating tridimensional molecular scaffolds from both a synthetic and a biological point of view. Among the many strategies developed to access these structures, transition metal catalysis has recently led to impressive advances, especially relying on the unique reactivity of the dearomatized spirocyclic intermediates. These species can indeed evolve toward both spirocyclic or nonspirocyclic products through rearomatization-driven processes, which are at the same time highly challenging to control but also a source of large structural diversity. This review highlights the most prominent methods of the past decade that involve a spirocyclization on indole derivatives tethered to a functional group that may be activated by a transition metal, leading to both spirocyclic and rearomatized products. The discussion is particularly focused on the reactivity of the spiroindoleninium intermediate and the complex mechanistic features regarding its evolution, which are highly dependent on the catalytic systems.