Caladan is a fictional planet in the Dune universe created by Frank Herbert.

Caladan, the third planet of Delta Pavonis, is the ancestral fiefdom of House Atreides, the birthplace of Paul Atreides and his home for fifteen years. The Atreides have lived on Caladan for twenty-six generations in the ancient Castle Caladan, after which they take up residence on Arrakis under political pressure.

The surface of the planet is predominantly covered with water and the planetary climate is characterised by abundant precipitation and strong winds, yet tolerable enough to make special and expensive weather control measures unnecessary. Habitable land is often characterised by soft meadows, swamps and dense forests. The resource base of Caladan consists mainly of agriculture and biomass, with the locally bred and grown Pundi Rice (see Dune terminology) being its main export and fishing a traditional source of sustenance for its people. Other traditional products include wine and various livestock, most prominently cattle. Cuisine on Caladan is rather refined, with most dishes containing meat.

Caladan has a strong military defense force based on naval and aerial superiority, and the people of Caladan are fiercely loyal to House Atreides. The elite forces of the Atreides army are even said to rival the emperor's Sardaukar in fighting prowess. Due to such military strength, Caladan is considered impregnable, which prompts the conspiracy of House Atreides' enemies to lure them to a more vulnerable position on Arrakis.

After the time of the novel God Emperor of Dune, it simply became known as Dan.