Abstract The synthesis of organic amines via reductive amination of biomass‐derived carbonyl compounds is an important target for sustainable chemical industries. The control of selectivity for the formation of primary amines versus secondary amines is challenging, and high temperature and pressures using H 2 are required to generate the desired selectivity. Herein, we report the highly selective reductive amination of a broad range of aldehydes and ketones by NH 3 and H 2 over Rh/MFM‐300(Cr) to form primary amines with a selectivity of up to 99% under ambient conditions. Inelastic neutron scattering reveals that the Rh species not only promote the hydrogenation process, but also catalyzes the ammonolysis of the Schiff base intermediate, facilitating the selective synthesis of primary amines. This protocol achieves selective reductive amination at 25 °C and 1 atm, providing an energy‐efficient route to a broad spectrum of amines.