Clube Operário Desportivo was founded in 1948 in Lagoa, on São Miguel island in the Azores, and is nicknamed Pica-Ferrugem in reference to its working-class origins. The club plays at the synthetic-pitch Estádio João Gualberto Borges Arruda, which holds 2,500 spectators. Operário competed in Série D of the Campeonato de Portugal, the fourth tier, in 2024-25; its honours include two Azores regional championships and two Terceira Divisão Série Açores titles.