Nitrogen is fundamental to all of life and to many industrial processes. Nitrogen in its various oxidation states comprises the global nitrogen cycle, with the change between forms being redox reactions involving electrons and protons. The interchange of nitrogen oxidation states constitutes some of the most important industrial processes, with the energy for these processes being provided largely by fossil fuel. A key goal of research in the field of nitrogen chemistry is to minimize the use of fossil fuels by developing more efficient heterogeneous, homogeneous, or biological catalysts, or by inventing new energy-efficient processes that rely on catalysts. These approaches, as well as the challenges involved, are discussed in this review. This review article reports on the current state of the field of nitrogen activation chemistry and discusses future directions.