Sir Thomas Brisbane is the only person who visited their namesake capital city in Australia.
The following is a list of Capital City (Australian State or Territory) and who they were named after:
Sydney (New South Wales) - Thomas Townshend, 1st Viscount Sydney
Melbourne (Victoria) -William Lamb, 2nd Viscount Melbourne
Hobart (Tasmania) -Robert Hobart, 4th Earl of Buckinghamshire (Lord Hobart)
Adelaide (South Australia) -Adelaide of Saxe-Meiningen, queen consort to King William IV
Darwin (Northern Territory) -Charles Darwin
From this list, only Charles Darwin had even set foot in Australia.
Sir Thomas was the 6th Governor of New South Wales and sent forth John Oxley in 1823 to find a northern convict settlement. With the help of shipwrecked convicts, Oxley discovered a river which he named the Brisbane. He returned in November 1824 with Sir Thomas on the Amity. Their party travelled by barge and a whale boat only 28 miles up the Brisbane River. Sir Thomas “occasionally landed, with fowling-piece in hand, to try his luck among the philomingies, curlews, and wild ducks”. The party even stayed up river in tents overnight.
So it is well documented that Sir Thomas travelled quite a distance up the river named after him, camped and set foot upon the soil of what was to become Queensland’s capital, Brisbane City.
All this fascinating information and more can be found at the following two Trove pages. Trove is a comprehensive digital resource for Australian newspaper articles from early 19th century to present day.
Sydney Gazette, December 9, 1824 (copied after) - Governor returns from Northern Settlements
The Australian, December 9, 1824 - The Governor and Moreton Bay (scroll up when opened)