| Alan George Semple | Director | 1 Aug 2000 | 13 May 2015 | British | 67 years |
| Allister Gordon Langlands | Director | 12 Aug 1991 | 14 May 2014 | British | 68 years |
| Arvind Philip Balan | Director | 15 Apr 2024 | 19 Feb 2025 | British | 46 years |
| Catherine Elisa Michel | Director | 10 May 2024 | 18 Jun 2025 | American | 55 years |
| Charles Nicholas Brown | Secretary | 3 Aug 1989 | 7 Apr 1998 | British | - |
| Christopher Edward Milne Watson | Secretary | 1 Oct 1999 | 24 Nov 2003 | British | - |
| Christopher Masters | Director | 18 Mar 2002 | 10 May 2012 | British | 79 years |
| David Charles Lockwood | Director | 12 Mar 2024 | 18 Jun 2025 | British | 64 years |
| David John Ogren | Director | 15 Mar 2001 | 11 May 2011 | American | 83 years |
| David Keith Woodward | Director | 23 May 2007 | 11 May 2016 | British | 80 years |
| David Miller Kemp | Director | 13 May 2015 | 14 Apr 2024 | British | 56 years |
| Edwin Charles Garrett | Director | 3 Aug 1989 | 31 Dec 2000 | British | 94 years |
| Ewan Brown | Director | 3 Aug 1989 | 17 May 2006 | British | 84 years |
| Graham Good | Secretary | 7 Apr 1998 | 1 Oct 1999 | British | - |
| Harry Brill-edwards | Director | 1 Nov 2000 | 30 Nov 2000 | American | 85 years |
| Hugh Drummond Duncan | Director | 3 Aug 1989 | 31 Aug 1994 | British | 89 years |
| Ian Clark Wood | Director | 3 Aug 1989 | 31 Oct 2012 | British | 84 years |
| Ian Derek Marchant | Director | 19 May 2006 | 1 Sept 2019 | British | 65 years |
| Ian Johnson | Secretary | 24 Nov 2003 | 1 Sept 2010 | British | - |
| Ian Philip Mchoul | Director | 6 Oct 2017 | 5 Apr 2018 | British | 66 years |
| Jacqueline Ferguson | Director | 1 Dec 2016 | 9 May 2024 | British | 56 years |
| James Bryon Renfroe | Director | 26 Feb 2008 | 26 Apr 2011 | American | 73 years |
| James Cooper | Director | 17 Feb 1993 | 31 Dec 1993 | British | 82 years |
| James Ramsay Spence | Director | 3 Aug 1989 | 6 Dec 1996 | British | 94 years |
| Janice Margaret Brown | Director | 15 May 2014 | 1 Sept 2019 | British | 71 years |
| Jeremy Richard Wilson | Director | 1 Aug 2011 | 29 Jun 2020 | British | 62 years |
| John Charles Morgan | Director | 29 Oct 1998 | 10 May 2012 | British | 81 years |
| John Derek Prichard Jones | Director | 3 Aug 1989 | 31 Dec 1998 | Us Citizen Naturalis | 91 years |
| Leslie James Thomas | Director | 19 May 2004 | 30 Jun 2012 | British | 69 years |
| Linda Louise Adamany | Director | 6 Oct 2017 | 1 May 2019 | American | 74 years |
| Mark Harry Papworth | Director | 16 Jan 2006 | 30 Jun 2012 | British | 61 years |
| Mark Stephen Dobler | Director | 1 Jan 2013 | 9 Oct 2013 | American | 63 years |
| Martin James Mcintyre | Secretary | 18 Dec 2017 | 30 Jun 2024 | - | - |
| Mary Louise Shafer-malicki | Director | 1 Jun 2012 | 13 May 2021 | American | 66 years |
| Michael Rasmuson | Secretary | 1 Jul 2024 | 1 Dec 2024 | - | - |
| Michael Straughen | Director | 1 May 2007 | 31 Aug 2014 | British | 76 years |
| Michel Jean Marcel Contie | Director | 24 Feb 2010 | 13 May 2015 | French | 79 years |
| Mitchell Scott Semple | Director | 3 Aug 1989 | 2 Aug 1991 | British | 83 years |
| Neil Heath Smith | Director | 1 Nov 2004 | 31 Dec 2013 | American | 62 years |
| Richard John Howson | Director | 12 May 2016 | 17 Jan 2018 | British | 58 years |
| Robert Keiller | Director | 20 Apr 2011 | 31 Dec 2015 | British | 62 years |
| Robert Muirhead Birnie Brown | Secretary | 1 Sept 2010 | 31 Dec 2015 | - | - |
| Roberto Monti | Director | 15 Mar 2001 | 31 Dec 2009 | British | 87 years |
| Robin Watson | Director | 1 Jan 2013 | 1 Jul 2022 | British | 59 years |
| Susan Steele | Director | 31 Mar 2021 | 18 Jun 2025 | American | 74 years |
| Thomas Botts | Director | 8 Jan 2013 | 22 Jun 2022 | American | 71 years |
| Thomas Motherwell | Director | 3 Aug 1989 | 1 Jun 2000 | British | 82 years |
| Trevor Mills Noble | Director | 19 May 2004 | 30 Apr 2007 | British | 80 years |
| Wendell Brooks | Director | 1 Jan 1999 | 28 Sept 2007 | American | 77 years |
| William Edgar | Director | 1 Sept 1995 | 19 May 2004 | British | 88 years |
| William George Setter | Secretary | 1 Jan 2016 | 18 Dec 2017 | British | - |
| William Hadden Carr | Director | 3 Aug 1989 | 30 Jun 1997 | British | 93 years |
