The Grenville orogeny was an episode of mountain-building (orogeny) associated with the assembly of the ancient supercontinent Rodinia. The Grenville orogeny occurred in the late Proterozoic eon, 1300-1000 million years ago (mya), as numerous continental plates collided around the edges of North America, forming folded mountains. In a narrow sense, the Grenville orogeny refers to the mountain ranges formed in western Europe and eastern North America, from Scotland southwest to Newfoundland and extending to North Carolina, 1100-1000 mya.
