There are 20 mathematicians whose last name begin with ORN.
| Orna, Miroslav | State University of New York at Albany | 2007 |
| Ornaghi, Mario | ||
| Ornaghi, Mattia | Università degli Studi di Milano | 2018 |
| Ornan, Uzi | ||
| Ornas, Jr., Gerard | Texas Tech University | 2003 |
| Ornatsky, Alexander | University of Pennsylvania | 2007 |
| Orndorff, Casey O. | Louisiana Tech University | 2016 |
| Orndorff, Mark | Florida State University | 2017 |
| Ornea, Liviu | University of Bucharest | 1992 |
| Ornek, Turkmen | Middle East Technical University | 2018 |
| Ornelas, Antonio | Scuola Internazionale Superiore di Studi Avanzati (SISSA) | 1988 |
| Ornelas, Emanuael | University of Wisconsin-Madison | 2002 |
| Ornelas Tellez, Fernado | Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN) | 2011 |
| Ornstein, Abraham | Rutgers University, New Brunswick | 1966 |
| Ornstein, Donald | The University of Chicago | 1957 |
| Ornstein, Leonard | Universiteit Leiden | 1908 |
| Ornstein, Luuk | Universiteit Utrecht | 1964 |
| Ornstein, Maya | University of Colorado at Boulder | 2023 |
| Ornstein, Peter | ||
| Ornstein, Petra | Uppsala Universitet | 2022 |