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 | |
|---|---|---|---|
| Mitchell, Prof. Samuel | Canada/USA | 1958 | 1960 |
| Stebbins, Dr. Joel | USA | 1958 | 1966 |
| Bowen, Dr. Ira S. | USA | 1956 | 1973 |
| Lindblad, Dr. Bertil | Sweden | 1956 | 1965 |
| Unsöld, Dr. Albrecht | Germany | 1956 | 1995 |
| Baade, Dr. Wilhelm Heinrich Walter | Germany | 1954 | 1960 |
| Oort, Dr. Jan Hendrik | Netherlands | 1954 | 1992 |
| Stratton, Prof. Frederick John Marrian | United Kingdom | 1954 | 1960 |
| Hubble, Dr. Edwin Powell | USA | 1951 | 1953 |
| Spencer Jones, Sir Harold | United Kingdom | 1947 | 1960 |