Funds, angels and corporates active in European rounds
| Investor | Type | Deals | Companies | Top sector | Active |
|---|---|---|---|---|---|
| OMERS Capital Markets | — | 2 | 1 | Cleantech | 2021–2022 |
| OMR X | Venture capital | 2 | 2 | Software | 2022–2023 |
| Omri Amir | Angel | 2 | 1 | HRtech | 2021–2022 |
| OMV | Corporate | 2 | 2 | Energy | 2022–2024 |
| OMV Petrom | Corporate | 2 | 2 | Energy | 2024–2025 |
| OnDeck Venture | Venture capital | 2 | 2 | Fintech | 2022 |
| One Equity Partners | — | 2 | 2 | Robotics | 2020–2024 |
| One Way Ventures | Venture capital | 2 | 2 | Healthtech | 2021–2022 |
| Ontario Teachers’ Pension Plan Board | Venture capital | 2 | 2 | Fintech | 2022 |
| Onza Capital | Investment firm | 2 | 1 | E-commerce | 2014–2015 |
| OOE Hightechfonds | Investment firm | 2 | 2 | Software | 2016–2021 |
| OP Finland Infrastructure LP | Venture capital | 2 | 1 | Energy | 2024–2025 |
| Openseed | Venture capital | 2 | 2 | Deeptech | 2026 |
| OpenT | Venture capital | 2 | 2 | Legaltech | 2025–2026 |
| The Operating Group | Venture capital | 2 | 2 | E-commerce | 2023–2025 |
| Operator Collective | Venture capital | 2 | 2 | AI | 2021–2025 |
| Operator Stack | Venture capital | 2 | 2 | Fintech | 2023–2026 |
| Opes Italia | Venture capital | 2 | 2 | Agritech | 2023–2025 |
| Opes Italia SICAF EuVECA | Venture capital | 2 | 2 | E-commerce | 2023–2024 |
| Optiver PSI | Venture capital | 2 | 2 | Fintech | 2022–2024 |
| Optiverder B.V | Venture capital | 2 | 2 | Healthtech | 2022–2026 |
| Orbit Startups | Venture capital | 2 | 2 | Healthtech | 2024–2025 |
| Orbita Verticale | Venture capital | 2 | 1 | HRtech | 2024–2025 |
| Orbital Ventures space fund | Venture capital | 2 | 2 | Fintech | 2021 |
| Orchard Participations | Venture capital | 2 | 2 | Cleantech | 2023–2024 |
