The Pummerer rearrangement, also called the Pummerer reaction, and its variants (Pummerer‐type transformations) are extremely useful tools in organic synthesis. The chapter is divided into six different sections. The first four describe the five types of Pummerer reactions, then a few examples of cascades or tandem processes with the participation of the Pummerer reaction are presented. The penultimate section is used to highlight recent applications in selenium‐Pummerer variants, and finally, a summary and outlook is provided. The types of Pummerer reactions covered here are: classical Pummerer reaction, vinylogous Pummerer reaction, interrupted and additive Pummerer reactions, connective Pummerer reaction, and Pummerer rearrangement in multiple‐reaction processes. The examples presented herein showcase the enormous variety of structures that can be obtained by Pummerer chemistry.