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 | |
|---|---|---|---|
| Hawking, Dr. Stephen W. | England | 1985 | 2018 |
| Bateson, Dr. Frank M. | New Zealand | 1984 | 2006 |
| Baldwin, Dr. Ralph Belknap | USA | 1980 | 2011 |
| Sandage, Dr. Allan R. | USA | 1975 | 2010 |
| Dollfus, Dr. Audouin C. | France | 1975 | 2011 |
| Goldberg, Dr. Leo | USA | 1974 | 1988 |
| Ryle, Sir Martin | United Kingdom | 1973 | 1983 |
| Iwanowska, Dr. Wilhelmina | Poland | 1973 | 1999 |
| van de Hulst, Prof. Hendrik | Netherlands | 1968 | 2000 |
| Strömgren, Prof. Bengt G. | Denmark | 1968 | 1987 |