Luminescent Mn(ii) complexes have attracted extensive attention owing to their properties of color tunability, high PLQYs, large Stokes shifts and thermal stability. Luminescent Mn(ii) complexes can exhibit orange, green, and red emissions depending on the environment of Mn. These various properties made Mn(ii) complexes attractive candidates for different fields of applications such as LEDs and radiation detection. In this perspective, we connect the emissions of Mn(ii) complexes with the corresponding crystal structure and the environment of Mn. Then, we summarize the recent progress of luminescent Mn(ii) complexes in LEDs and radiation detection. Finally, we present the challenges and outlook for future research on luminescent Mn(ii) complexes.