Murtho is a locality in South Australia. It is northeast of Renmark and Paringa. It is bounded by the Murray River on its north and west sides and the Victorian border on the east. Land around Murtho today is used for vineyards and orchards irrigated from the Murray River, and cereal crops. It has a boat ramp and shop which supports campers and recreational fishing. Before Australian federation in 1900, Murtho was the site of the South Australian customs house known as Border Cliffs, charging import duty on goods being brought down the river from New South Wales and Victoria.