<p>Green, one of the three primary colors, plays a crucial role in electroluminescent (EL) devices, making green EL materials a vital component of organic light-emitting diodes (OLEDs). However, to date, there has been no systematic review specifically focusing on the research progress of green EL materials. In this review, we have not aimed to list narrow-band green EL materials exhaustively. Instead, our main goal is to provide a focused, in-depth analysis that highlights the essential role of green emitters in modern optoelectronic technology. We systematically examine the core design strategies underlying high-performance narrow-band green electroluminescent materials, analyzing critical factors such as molecular engineering, excited-state characteristics, and device architecture to elucidate the relationship between molecular structure and the position, bandwidth, and emission properties of the emission peaks. By synthesizing these vital insights, this work aims to provide valuable theoretical foundations and practical guidance, helping researchers rationally and efficiently develop next-generation, high-performance green-emitting materials for advanced display and lighting applications.</p>