Alfredo Keil was a Portuguese classical composer and painter. He was of German origin on his father’s side, and was the great Portuguese romantic composer. He was also considered the last important Portuguese painter in the romantic style. He studied in Munich and Nuremberg with the German romantic painters Kaulbach and von Kreling. Returning to Portugal, were he continued his studies, he became a well known romantic painter, being also the contemporary of the naturalist generation, with his melancholic intimate scenes and landscapes. As a composer, he gained prominence with his operas "D. Branca" (1883), "Irene" (1893) and "Serrana" (1899), then considered the best Portuguese opera.

He composed the music of A Portuguesa, the Portuguese national anthem, in 1891, with lyrics by poet and playwriter Henrique Lopes de Mendonça; it was adoped in 1911, after the proclamation of the Republic the previous year.