Phosphorescent manganese(II) complexes are emerging as a new generation of phosphorescent materials showing great potentials in many applications, owing to their unique features including highly efficient phosphorescence, diverse structural/molecular design, and ease of synthesis, structural diversity, rich physical properties (e.g., triboluminescence, stimuli‐responsivity, etc.), high abundance, and low cost. The research on phosphorescent manganese(II) complexes is just in its infancy but rapidly flourishing indeed, and their potential applications are also emerging in many aspects. Herein, the recent progress on the molecular design of new manganese(II) complex‐based materials, mechanism of phosphorescence, photophysical properties, and their representative applications is highlighted, which covers topics such as: i) structural features and photophysics of phosphorescent manganese(II) complexes; ii) molecular design strategies of phosphorescent manganese(II) complexes (e.g., neutral complexes, ionic complexes, coordination polymers, and other types of complexes); and iii) their emerging applications in the fields of organic electroluminescence, information recording and security protection, temperature sensors. Finally, some perspectives together with future research focus of the field are described. Compared with the noble metals, manganese has abundant reserves, is environmentally friendly, and inexpensive. Phosphorescent manganese(II) complexes are emerging as a new generation of phosphorescent materials with great potential in many application areas. An overview of the molecular design, synthesis, photophysics, and recent research progress on phosphorescent manganese(II) complexes and their emerging applications is provided.