| 1000032989 | Ommatidia Lidar S.L. | ES-Spain | Company | Yes | Alumnus | ESA BIC Madrid Region | |
| 1000048815 | Oniro S.r.l. | IT-Italy | Company | Yes | Alumnus | ESA BIC Lazio | |
| 1000043603 | onocoy Services AG | CH-Switzerland | Company | Yes | Alumnus | ESA BIC Switzerland | |
| 1000024861 | Open Cosmos Ltd. | GB-United Kingdom | Company | Yes | Alumnus | ESA BIC UK | |
| 1000027054 | OPT ALM | FR-France | Company | No | Alumnus | ESA BIC Sud France | |
| 1000044838 | Optocycle GmbH | DE-Germany | Company | No | Alumnus | ESA BIC Baden-Württemberg | |
| 1000042239 | OPUS Aerospace | FR-France | Company | No | Alumnus | ESA BIC Nord France | |
| 1000029654 | Orbital Astronautics | GB-United Kingdom | Company | Yes | Alumnus | ESA BIC UK | |
| 1000030848 | ORBITAL CARGO DRONE LTD | GB-United Kingdom | Company | No | Alumnus | ESA BIC UK | |
| 1000042990 | Orbital Matter Poland Sp. z o.o. | PL-Poland | Company | Yes | Alumnus | ESA BIC Poland | |
| 1000040177 | Orbital Outpost Italy S.R.L. | IT-Italy | Company | No | Alumnus | ESA BIC Turin | |
| 1000043214 | Orbital Paradigm | ES-Spain | Company | Yes | Alumnus | ESA BIC Madrid Region | |
| 1000029399 | Orbital Witness Limited | GB-United Kingdom | Company | No | Alumnus | ESA BIC UK | |
| 1000044988 | Oris | IT-Italy | Company | No | Alumnus | ESA BIC Turin | |
| 1000043764 | O-Robotics ApS | DK-Denmark | Company | Yes | Alumnus | ESA BIC Denmark | |
| 1000031454 | OroraTech GmbH | DE-Germany | Company | Yes | Alumnus | ESA BIC Bavaria | |
| 1000045195 | Oshen Ltd | GB-United Kingdom | Company | No | Alumnus | ESA BIC UK | |
| 1000042598 | OSMIUM ITALY S.R.L. | IT-Italy | Company | Yes | Alumnus | ESA BIC Turin | |
| 1000046288 | Osmos X | FR-France | Company | Yes | Incubatee | ESA BIC Nord France | |
| 1000036590 | OUR WATCH LEADS - OWL, LDA | PT-Portugal | Company | Yes | Alumnus | ESA BIC Portugal | |