Coordinates: 21°38′24″S 41°03′03″W / 21.64000°S 41.05083°W
São João da Barra (Portuguese pronunciation: [sɐ̃w ˈʒwɐ̃w dɐ ˈbaʁɐ]) is a municipality located in the Brazilian state of Rio de Janeiro. Its population was 28,609 (2005) and its area is 459 km². It is home to the Superporto do Açu.