Summary of main observation and conclusion A new class of indole‐based allylic donors have been designed and developed for palladium‐catalyzed decarboxylative allylations. In addition, the first application of these indole‐based allylic donors in palladium‐catalyzed decarboxylative 3+2 cycloaddition and allylic amination has been achieved by reacting with isocyanates and sulfonyl amines, respectively. This approach represents the first design of indole‐based allylic donors, which is helpful for settling the challenge of designing and developing new class of heterocycle‐based allylic donors for Pd‐catalyzed decarboxylative allylation reactions. Moreover, the application of this new class of allylic donors in cycloadditions and substitutions will add new contents to the research field of decarboxylative allylation. A new class of indole‐based allylic donors have been designed and applied in palladium‐catalyzed decarboxylative 3+2 cycloaddition and allylic amination.