| Name | Functions  | Event Dates | Events | Resources | ||
|---|---|---|---|---|---|---|
| José Luis Alonso | Director | 1982 | 3 | |||
| Richard Albert | Director | 1991 | 1 | 1 | ||
| Detlef Altenbeck | Director | 1994 - 2005 | 2 | 1 | ||
| Carlos Aguilera | Director | 1994 - 1997 | 2 | |||
| Mary Arbenz | Director | 1967 | 1 | |||
| Martin Ankermann | Director | 1965 - 1967 | 2 | |||
| Folke Abenius | Director | 1966 | 1 | |||
| Ruy Antunes | Director | 1966 | 1 | |||
| Erwin Arlt | Director | 1965 | 1 | |||
| Wolfram Apprich | Director | 2000 - 2014 | 16 | |||
| T. Achramkova | Director | 2002 | 1 | |||
| Bill Alexander | Director | 2002 | 1 | |||
| Norman Armour | Director | 2002 | 1 | |||
| Róbert Alföldi | Director | 2012 - 2018 | 2 | |||
| Juraj Augustín | Director | 2013 | 1 | |||
| Chris Abraham | Director | 2003 | 1 | 1 | ||
| Jan Aust | Director | 2001 - 2008 | 4 | |||
| Jörn Arens | Director | 2004 | 1 | |||
| Kristian Almqvist | Director | 2004 | 1 | 1 | ||
| Nicholas C. Avila | Director | 2001 | 1 | |||
| Laurent Azimioara | Director | 2006 | 1 | |||
| Maja Ardal | Director | 2007 | 1 | |||
| María Herminia Avellaneda | Director | 1972 - 1997 | 2 | |||
| Nathalie Adlam | Director | 2015 | 1 | |||
| Andy Arnold | Director | 2015 | 1 | |||
| Carolyn Anderson | Director | 2006 | 1 | |||
| Kathleen Amshoff | Director | 2007 | 1 | |||
| Chamat Arambewela | Director | 2008 | 1 | |||
| Erich Anzelewsky | Director | 1942 | 1 | |||
| Gustav Amberg | Director | 1890 | 1 | |||
| Shayan Afkari | Director | 2010 | 1 | |||
| Paula Rojas Amador | Director | 2010 | 1 | |||
| Keval Arora | Director | 2010 | 1 | 1 | ||
| Walter Sigi Arnold | Director | 2016 | 1 | |||
| Ramin Anaraki | Director | 2013 | 1 | |||
| Dan Alecsandrescu | Director | 1969 - 1994 | 5 | |||
| Arin Arbus | Director | 2016 | 1 | |||
| Pierre Arnaudeau | Director | 1960 - 1963 | 2 | 1 | ||
| Staffan Aspelin | Director | 1961 | 1 | |||
| T. O. Andrus | Director | 1961 | 1 | 1 | ||
| Sherwin Abrams | Director | 1960 | 1 | 1 | ||
| Ian Appleby | Director | 2011 | 1 | |||