| 23 June 1860 | Born Lancashire, England. |
| 1884 | Graduated from Oxford (BA) |
| 1886 | Lincoln College Fellow |
| 1887 | Appointed to the foundation chair of biology at the University of Melbourne |
| 1888 | Foundation of the Australian Association for the Advancement of Science. Spencer attended inaugural meeting of the Associaton, and the Protection of Native Birds and Mammals Committee formed following a motion by Spencer. |
| 1890 | Appointed first Victorian Secretary of the Australian Association for the Advancement of Science |
| 1891 - 1893 | President of the Field Naturalists' Club of Victoria |
| 1894 | Zoologist and Photographer in Horn Expedition |
| 1895 | Ttrustee of the National Gallery of Victoria |
| 1895 - 1897 | President of the Field Naturalists' Club of Victoria |
| 1899 | Honorary Director of the Natural Museum of Victoria |
| 1899 | Honorary Director of the National Museum of Victoria |
| 1900 | Awarded FRS |
| 1904 | Awarded CMG |
| 1904 | President of the Royal Society of Victoria |
| 1904 | President of the Royal Society of Victoria |
| 1907 | Spencer suggests to the Government that it set up a committee to advise the government on all matters concerned with the preservation or destruction of Australian fauna, i.e. national parks. |
| 1916 | Awarded KCMG |
| 1919 | Retired as Emeritus Professor |
| 1928 | Resignation as Director of the Natural Museum of Victoria |
| 14 July 1929 | Died Navarin Island, Tierra del Fuego. |