Antonio Joaquim de Castro Feijó (Ponte de Lima , on June 1 of 1859 - Stockholm , June 20 of 1917 (58 years)) was a Portuguese poet and diplomat.

He studied in liceais Braga and studied law at Coimbra University completing the course in 1883.

In 1886 he joined the diplomatic service. He held senior positions in Brazil (consulates of Pernambuco and Rio Grande do Sul) and from 1895 in Sweden and in Norway and Denmark.

He married on September 24 of 1900 with Sweden's Maria Luisa Carmen Mercedes Joanna Lewin (born August 19, 1878), whose untimely death on September 21, 1915, was to influence his work.

As a poet, Antonio Feijo is usually linked to Parnassianism.