Bartolomeu Dias was a 15th Century Portuguese sailor known for leading the first European expedition known to round the southern tip of Africa.

He was born about 1450 in Portugal. Little else is known of his birth or even of his early life. One of his ancestors is known to have been an explorer as well.

In 1481, Dias went with Diogo de Azambuja to established a trading post in the Gulf of Guinea. He went on other voyages down the western coast of Africa during this time as well. And it was in 1486 that the Portuguese king, John II, commissioned him to find a way to sail around the southern tip of Africa. Portugal was leading the way during the Age of Exploration, and John wanted to establish a trade route to the east that didn't depend on a long travel time overland.

Another part of Dias's mission was one shared by other explorers, from Portugal and from other European powers–to find the fabled Christian leader Prester John, whose realm was said to be somewhere to the east, perhaps in Africa or perhaps in Asia.

Dias set out in the summer of 1487. He had three ships: two caravels, the São CristóvŇo and the São Pantaleão, and one supply ship. They had ranged far to the south by the end of the year and then turned away from the coast, whether driven by a storm or by choice. As it turned out, they found winds favorable for their task and, in early 1488, rounded the Cape of Good Hope. Dias originally named it the Cape of Storms. They found land on February 3, at what is now Mossel Bay. They continued on but, lacking supplies, turned around, on March 12, and headed for home. Before leaving, they planted yet another padrão, a carved stone pillar that the Portuguese sailors used to mark their progress.

The successful sailor returned to his king's court to report but met initially with little fanfare. Dias went to live in Africa for a time and then King Manuel I named him to accompany Vasco Da Gama on his historic voyage to India in 1498. (Dias stayed behind in the Cape Verde Islands while Da Gama went on to Calcutta.)

In 1500, Dias was back on the open ocean, sailing with Pedro Álvares Cabral on the second Portuguese expedition to India. They were the first to reach Brazil, arriving there on April 22, 1500, before turning east. The following month, a large storm claimed four of Cabral's ships and the lives of many of his crews, including Dias. They were missing and presumed dead on May 29.

Dias is known to have married (although her name is unknown) and to have had two children, Simão Dias de Novais and António Dias de Novais.