Honorary Membership was limited to 10 from 1890-1900, and to 15 from 1901 onwards. Corresponding Membership was a lesser class of Honoris causa membership in the early years. A few honorary members, such as Barnard, were first made corresponding members for a short time before being recommissioned as honorary members.
| Nation(s) | Start | End | |
|---|---|---|---|
| Darwin, Dr. Sir George Howard | United Kingdom | 1894 | 1912 |
| Denning, Mr. William F. | United Kingdom | 1891 | 1931 |
| Dollfus, Dr. Audouin C. | France | 1975 | 2011 |
| Downing, Dr. Arthur Matthew Weld | United Kingdom | 1896 | 1917 |
| Dyson, Sir Frank Watson | United Kingdom | 1916 | 1939 |
| Elger, Mr. Thomas Gwyn Empy | United Kingdom | 1896 | 1897 |
| Espin, Rev. Thomas Espinell | United Kingdom | 1894 | 1934 |
| Evans, Rev. Robert O. | Australia | 1993 | 2022 |
| Flammarion, M. Camille | France | 1901 | 1925 |
| Fleming, Dr. Sir Sandford | Canada | 1890 | 1915 |