R Doradus is a red giant variable star in the far-southern constellation Dorado. Its distance from Earth is 178 light-years. Having a uniform disk diameter of 57±5 mas, it is thought to be the extrasolar star with the largest apparent size as viewed from Earth.

Dorado is a constellation in the Southern Sky. It was named in the late 16th century and is now one of the 88 modern constellations. Its name refers to the mahi-mahi, which is known as dorado ("golden") in Spanish, although it has also been depicted as a swordfish. Dorado contains most of the Large Magellanic Cloud, the remainder being in the constellation Mensa. The South Ecliptic pole also lies within this constellation.