A volcanic island in the southern Ross Sea, located at approximately 78°S and 168°E and roughly triangular in shape. Ross Island was the base for several expeditions of the Heroic Age of Antarctic Exploration.

The reason for such continuing interest in this particular island is that part of the western coast forms pretty much the most southerly port in the world whilst the island allows fairly easy access to the Ross Ice Shelf and a broad road towards the pole. Erebus is an active volcano, whilst Cape Crozier, on the island's eastern end, is home to a large Emperor Penguin colony. The island also has good numbers of seals and multiple Adelie Penguin colonies.

The volcanoes of Ross Island were first seen (and named Erebus and Terror) by James Clark Ross in 1841, as was a bay he named McMurdo. However, it was not until Robert Falcon Scott's first expedition arrived in early 1902 that these volcanoes were determined to form a separate island and McMurdo was, in fact, a sound. Scott also discovered that there was a well sheltered bay nestled betweens arms of lava and which was named Winter Quarters Bay for reasons which should be fairly obvious. He built a shore base at Hut Point and his ship, Discovery was iced in for two winters whilst he and his men carried out a wide scientific and geographical program.

In 1908, Shackleton, who had been part of Scott's team for the first winter, found that the best place for his attempt on the South Pole happened to be just around the corner at Cape Royds. Though he didn't make it to the Pole, Douglas Mawson got his Antarctic start by, amongst other things, climbing Erebus. Next, Scott returned to Ross Island to set up another base at Cape Evans and head south himself. The last tenant, for this period, were men of the Aurora. These were part of Shackle's attempt to cross the continent. A grim time was had by all and several of the Aurora shore party died in the process.

Ross Island was pretty much left alone for some decades after that. It wasn't really until the IGY period that humans returned, with the Americans building McMurdo Station next door to Scott's Discovery hut on the seaward shore and New Zealand building Scott Base through the gap on the ice side. The area has been continuously occupied since.