The Ikarus IO (Serbian Cyrillic:Икарус ИО – Извиђач Обални) was a biplane flying boat produced in Yugoslavia in the late 1920s. It was a conventional flying boat design for its day, featuring a large single-bay wing cellule, the staggered wings of slightly uneven span braced with N-struts. The pilot and observer sat side by side in an open cockpit, and a gunner sat in an open position ahead of them, in the bow. The pusher engine and frontal radiator were carried on struts in the inter-plane gap.