The efficient production of ammonia (NH3) from dinitrogen (N2) and water (H2O) using renewable energy is an important step on the roadmap to the ammonia economy. The productivity of this conversion hinges on the design and development of new active catalysts. In the wide scope of materials that have been examined as catalysts for the photo- and electro-driven reduction of N2 to NH3, functional metal-organic framework (MOF) catalysts exhibit unique properties and appealing features. By elucidating their structural and spectroscopic properties and linking this to the observed activity of MOF-based catalysts, valuable information can be gathered to inspire new generations of advanced catalysts to produce green NH3. NH3 is also a surrogate for the hydrogen (H2) economy, and the potential application of MOFs for the practical and effective capture, safe storage, and transport of NH3 is also discussed. This Perspective analyzes the contribution that MOFs can make toward the ammonia economy.