The Thomson River, a perennial river of the West Gippsland catchment, is located in the Gippsland region of the Australian state of Victoria.

Victoria is a state in southeastern Australia. It is the second-smallest state, with a land area of 227,444 km2 (87,817 sq mi); the second-most-populated state, with a population of over 6.7 million; and the most densely populated state in Australia. Victoria is bordered by New South Wales to the north and South Australia to the west and is bounded by the Bass Strait to the south, the Great Australian Bight portion of the Southern Ocean to the southwest, and the Tasman Sea to the southeast. The state encompasses a range of climates and geographical features from its temperate coastal and central regions to the Victorian Alps in the northeast and the semi-arid northwest.