Guild Wars Nightfall is a fantasy MMORPG and the third stand-alone campaign in the Guild Wars computer game series developed by Seattle-based game developer studio ArenaNet, a subsidiary of NCSoft corporation. Nightfall was released worldwide on October 27, 2006 after beginning in development in November 2005.

Nightfall takes place in the continent of Elona in the Guild Wars universe. It follows the player's character as they join the Order of the Sunspears and uncover the desire of Warmarshal Varesh to return a long forgotten god to the world through an event called Nightfall. The player, assisted by their hero allies, fight through civil war, ignorant Vabbi princes and Varesh's demon allies as they attempt to prevent the coming of Nightfall.