Mean diameter: approximately 1,527 km · Orbits Saturn.
Saturn’s second-largest moon narrowly outranks Oberon by the central size estimates used here. Rhea’s cold surface is heavily cratered; it rotates once per orbit, keeping the same side toward Saturn.
The bright-looking world is much smaller than Titan. Rhea also illustrates why “largest” needs a defined measurement: this list compares diameter, and the close Rhea–Oberon order is not a claim of certainty beyond the measurements.
Sources: NASA moon guide · JPL size data.
Image source: NASA/JPL/Space Science Institute; reuse terms. Resized and JPEG-compressed.