HMS Investigator was the mercantile Fram, launched in 1795, which the Royal Navy purchased in 1798 and renamed HMS Xenophon, and then in 1801 converted to a survey ship under the name HMS Investigator. In 1802, under the command of Matthew Flinders, she was the first ship to circumnavigate Australia. The Navy sold her in 1810 and she returned to mercantile service under the name Xenophon. She was probably broken up c.1872.

Captain Matthew Flinders was a British navigator and cartographer who led the first inshore circumnavigation of mainland Australia, then called New Holland. He is also credited as being the first person to utilise the name Australia to describe the entirety of that continent including Van Diemen's Land, a title he regarded as being "more agreeable to the ear" than previous names such as Terra Australis.