An organic electroluminescence device of an embodiment may include a first electrode, a hole transport region disposed on the first electrode, an emission layer disposed on the hole transport region, an electron transport region disposed on the emission layer, and a second electrode disposed on the electron transport region. The electron transport region may include a first compound represented by Formula 1, thereby improving the moving speed of electrons. Accordingly, the organic electroluminescence device of an embodiment may show decreased driving voltage and improved efficiency.