Dinis Dias was a 15th-century Portuguese explorer.
In 1445, as Dias was beginning to enter old age and made the decision to take up exploring because "he was unwilling to let himself grow soft in the well being of repose", left Portugal and sailed down the West African coast, setting a new record by reaching a point about 800 kilometres south of Cap Blanc. This, the most westerly part of the African continent, he named Cap-Vert (Dias named it Cabo Verde, "verde" being Portuguese for "green", a reference to the lush vegetation in the area). Note that Dias did not discover the Cape Verde Islands, but rather the actual cape.
The success of this expedition was probably because Dias concentrated on exploration, rather than taking slaves, a pursuit most Portuguese mariners in Africa at the time focused on. Whereas some expeditions would return to Portugal with dozens of slaves, Dias only took four captives.
Later that year, Dias sailed with the explorer Lançarote de Freitas in a large scale slaving expedition to Arguim.