The Hundred of Monarto is a cadastral unit of hundred, the centre of which lies about 47 kilometres (29 mi) east southeast of Adelaide in South Australia and about 19 kilometres (12 mi) west of the Murray River. One of the ten hundreds of the County of Sturt, it is bounded on the west by the Bremer River, with the north west corner being set at the point where Mount Barker Creek merges with the river. It was named in 1847 by Governor Frederick Robe after "Queen Monarto", an aboriginal woman who lived at the time in the area. According to John Wrathall Bull, in his writings on early South Australia history, she was the lubra (partner) of aboriginal tribal leader "King John", whose tribe resided "on the banks of the Murray" at the time.