Dehydrogenation of saturated N‐heterocycles and hydrocarbons provides an important route to corresponding aromatic compounds. Herein, an efficient and selective MnAlO‐catalyzed aerobic oxidative dehydrogenation of five‐ and six‐membered N‐heterocycles, imines and hydrocarbons is presented. The reaction features excellent yields of the products, mild reaction conditions, readily available and reusable catalyst. Various N‐heterocycles and hydrocarbons can be tolerated by the reaction system and transformed to the corresponding aromatic counterparts. Mechanistic studies revealed that the reaction proceeds mainly through an electron transfer mechanism. [ABSTRACT FROM AUTHOR]