Since 2009, the Old Testament scholar John Walton has produced a series of short books for laypeople which assert the existence of a “lost world” behind key parts of the Old Testament, including The Lost World of Genesis One, The Lost World of Scripture (co-authored with D. Brent Sandy), The Lost World of Adam and Eve, The Lost World of the Israelite Conquest (co-authored with J. Harvey Walton), The Lost World of the Flood (co-authored with Tremper Longman III), The Lost World of Torah (co-authored with J. Harvey Walton), The Lost World of the Prophets, and, most recently, New Explorations in the Lost World of Genesis. For Walton, this lost world, a historical-conceptual background reconstructed from extrabiblical literature, is essential for understanding the Old Testament. This presentation will evaluate Walton’s arguments, especially in his books dealing with Genesis, and offer a critique, from the point of view of ancient Near Eastern literature and biblical exegesis.