NGC 3603 was observed by John Herschel on the 14th of March 1834 during his visit to South Africa, who remarked that it was "a very remarkable object...perhaps a globular cluster".
NGC 3603是約翰·赫歇爾在訪問南非時於1834年3月14日發現的，他的註記說這是一個非常顯著的天體……可能是一個球狀星團。