Caetano da Costa Alegre (April 26, 1864-April 18, 1890) was a Portuguese poet. Born to a Creole family in the Portuguese colony of São Tomé, off the coast of Africa, he settled in Portugal in 1882 and attended medical school in Lisbon, hoping to become a naval doctor, but died of tuberculosis before he could fulfill his dream.

In 1916, a friend, journalist Cruz Magalhãez published the poetry he wrote during the eight years Costa Alegre lived in Portugal. The work, written in the popular romantic style of the time, was an immediate success, not least because of how it celebrates his African origins, expresses longing for his home in São Tomé, and describes the sense of alienation he feels because of his race. He expresses his sorrow after being rejected by a white woman because of the color of his skin in one of the earliest attempts by an African poet to deal with issues of race.

Though distinctly European in style, the themes of Costa Alegre's work make him a precursor to later African authors and poets, who dealt with issues of race, alienation, and nostalgic reveries for the past (in his case, his reminiscences about São Tomé).