Keep on the Borderlands is a conversion of paper and pencil module written by Gary Gygax, first published by TSR in 1979. The paper and pencil module, The Keep on the Borderlands, was ranked the 7th greatest Dungeons & Dragons adventure of all time by Dungeon magazine in 2004, on the 30th anniversary of the Dungeons & Dragons game.

Players arrive at the Keep on the Borderlands, where they base themselves before investigating the Caves of Chaos, a series of nearby caverns full of humanoid tribes poised to destroy the keep. It typifies the dungeon crawls associated with beginning D&D players, while permitting some limited outdoor adventures.