Abel Acácio de Almeida Botelho (23 September 1855 or 1856 – 1917), was a Portuguese military officer and diplomat who distinguished himself as a writer. A representative of Naturalism in Portugal, he wrote, among others, O Barão de Lavos and O Livro de Alda, the first two titles in his "Patologia Social" series. In 1911, he took part in the commission that selected and approved the draft of what would become the current flag of Portugal.