Prelude to Foundation

Foundation: Volume 1

Foundation and Earth

Foundation and Empire

The Robots of Dawn

The Stars, Like Dust

The Caves of Steel: The Robot Series

Forward the Foundation

Foundation's Edge

Second Foundation

The Naked Sun

The Currents of Space

Pebble in the Sky

Prelude to Foundation (The Foundation Series: Prequels, Book 1)

I, Robot

Foundation (The Foundation Trilogy, Book 1)

Second Foundation (The Foundation Trilogy, Book 3)