Lieutenant Peter Belches (1796–1890) was an early explorer in Western Australia.
Born in Edinburgh, Scotland in 1796, Belches joined the Royal Navy in 1812. He was an officer on HMS Volage in December 1826, when it was anchored in Sydney Harbour along with HMS Warspite under Sir James Brisbane and HMS Success under Sir James Stirling. When Brisbane died on 19 December, Stirling made a number of promotions and re-appointments to cover for his loss. In the process, Belches was promoted to Third Lieutenant on the Success.
In March 1827, the Success arrived off the coast of the Swan River in what is now Western Australia to undertake an exploration expedition which aimed to determine the suitability of the area for establishing a British colony. After examining the coastal waters of the area, an 18-man land party was formed to explore up the river. As a member of the party, Belches traversed the Swan up to its junction with Ellen Brook. At the location now known as "The Narrows", Stirling named a peninsula on the southern side of the Swan Point Belches in Belches' honour.
At the junction of Ellen Brook, Stirling split the party into three groups, sending Belches and George Heathcote to explore to the north, where they found a fresh water lake. After returning to the junction of the Canning River, Stirling sent Belches to explore it. Belches traced the Canning for twenty miles( or 32 kilometres), returning after two days to report that it was a fresh water river "similar in every respect" to the Swan.