Palladium-catalyzed amination of aryl halides is widely used in the synthesis of N-aryl amine derivatives. N-Aryl amines have important applications as pharmaceuticals, agricultural chemicals, and electronic materials. This chapter provides a summary of the mechanism, the optimal choice of catalyst, and the scope of this important reaction. Application to the arylation of ammonia, amines, amide derivatives, hydrazines, N–H imines, and azoles are discussed. The strengths and limitations of the palladium-catalyzed methodology are compared to nickel- and copper-catalyzed amine arylation methods. Examples of the use of palladium-catalyzed amine arylation in the synthesis of pharmaceutical intermediates and natural products are highlighted.