Moso Island is an island off the northwest coast of Efate in Vanuatu, in Shefa Province. It is separated from Efate by , which is 200 metres (660 ft) wide at its narrowest point. Along with Lelepa, it creates the harbour at north Efate known as Port Havannah. This harbour was a focal point during World War II, with many troops stationed there, including posts on Moso itself. Today, small tokens of the soldiers' presence can still be seen on Moso.