| Name | Functions  | Event Dates | Events | Resources | ||
|---|---|---|---|---|---|---|
| Raymond Omodei | Designer, Director | 1974 - 2001 | 5 | |||
| Gisela Olroth-Hackenbroch | Designer, Director | 2011 | 2 | |||
| Reinhold Ockel | Designer, Director | 1927 - 1942 | 2 | |||
| Alexander Okun | Designer | 1992 - 2003 | 3 | 1 | ||
| Wilfried Otto | Designer | 1958 | 1 | |||
| Hugh Owen | Designer | 1927 | 1 | |||
| O. Orling | Designer | 1895 | 2 | |||
| E. Orling | Designer | 1895 - 1896 | 6 | |||
| Breitner og Bauer | Designer | 1897 | 1 | |||
| Helmut Obstfelder | Designer | 1949 | 1 | |||
| Saburonosuke Okada | Designer | 1909 | 1 | |||
| Knut Opperud | Designer | 1994 | 1 | |||
| Eva Cathrine Opstad | Designer | 2007 | 1 | |||
| Chloé Obolensky | Designer | 2011 | 1 | 1 | ||
| Bailey Otto | Designer | 2014 | 1 | |||
| Lenka Odvárková | Designer | 2009 - 2011 | 3 | |||
| Caitlin O'Hara | Designer | 2013 | 1 | |||
| Stephan Olson | Designer | 1990 | 1 | |||
| Louis O´Byrne | Designer | 1991 | 1 | |||
| Nick Ormerod | Designer | 1990 | 1 | 1 | ||
| Shinobu Okazaki | Designer | 1991 | 1 | |||
| Floor Oskam | Designer | 1991 - 1992 | 14 | |||
| Francis O'Connor | Designer | 2000 | 1 | |||
| Julia Trevelyan Oman | Designer | 1980 | 1 | |||
| David Oldman | Designer | 1996 | 1 | |||
| Cornelius Oswald | Designer | 2014 | 1 | 1 | ||
| Simon Oliver | Designer | 2002 | 1 | |||
| Sylvie Orcier | Designer | 2004 - 2005 | 9 | |||
| Tim O'Hare | Designer | 2004 | 1 | |||
| Laurian Oniga | Designer | 1985 | 3 | |||
| Alain Ortiz | Designer | 2006 | 3 | |||
| Solomon Ogazi | Designer | 2002 | 1 | |||
| Aigars Ozoliņš | Designer | 2008 | 1 | |||
| Max Julian Otto | Designer | 2008 - 2009 | 4 | |||
| Andrei Onegin | Designer | 2009 | 1 | |||
| James Ogden | Designer | 2009 | 1 | |||
| Katie Orwig | Designer | 2011 | 1 | |||
| Paul O'Mahony | Designer | 2013 - 2017 | 3 | |||
| Jens-Anker Olsen | Designer | 1954 - 1956 | 2 | |||
| Tony Owen | Designer | 2013 | 1 | |||
| Heinz Ockermüller | Designer | 1953 | 1 | |||
| Koji Okazaki | Designer | 1999 | 1 | |||