Captain's Flat is a sleepy little village nestled on the Molonglo River, among hills adjacent to the Jingera Mountains. There is some dispute as to the exact origins of how the town got its name. A Captain William Sawyer settled in the district in 1833. It was believed that he received land as a wedding gift from Governor Arthur (Tasmania) who had been his wife's former employer, but it was subsequently discovered that he in fact, only rented the land. Furthermore, it transpired that he was not a captain at all, but a private.

Some of the land was purchased by John Hosking which was used as grazing for Foxlow Station. After bankruptcy, he sold Foxlow Station to Thomas Rutledge of Carwoola Station, in 1868. John Hosking was not a captain, however a Captain Hosking did indeed settle in Captain's Flat in the 1890's but by then, the town already had its name. The next link to a captain came with James Trevarthen. He fossicked the area prior to the goldrush days in his capacity of mining supervisor for a company at Currawang near Collector.

The strongest link to any particular captain, appears to have been with the arrival in the Goulburn district of one Francis Nicholas Rossi. He came to Australia in 1825 in the capacity of General Superintendant of Convicts but had to surrender his land grants near Goulburn as he was not of British origins. Rossi's son, Count Francis Robert Louis Rossi was then given the land by Governor Gipps. Perhaps the influence of the Rossi captains and the close proximity of their lands gave name to Captain's Flat, but it does seem unlikely.

The favoured story as to how Captain's Flat got its name does not involve men at all, but rather a bullock. Legend has it that nearby Foxlow Station owned a gigantic white team bullock known as "Captain". Whenever work was to be done he would invariably be hiding somewhere, his favourite spot being a particular patch of river flat. Drovers travelling through the valley became so used to seeing "Captain" on his patch of grass that they began calling the area Captain's Flat. Apparently years later, the white bullock was found dead on the very spot which is now the Captains Flat playing field. Given the Australian bush psyche, by which men of title were far less respected than fine beasts, this last story does indeed seem to be the most plausible.