Oxford Quantum Circuits (OQC), the UK-based scaleup building and deploying quantum computers, has raised a £260m ($350m) Series C. The raise marks the biggest ever funding round ever by a private quantum computing company in Europe, following a $600m equity raise bagged by UK- and US-based Quantinuum in 2025. The Series C is the fourth megaround ($100m+) raised by a quantum computing company in Europe since the start of the year, already surpassing three that were announced across all of 2025, and reflecting sustained investor interest in the sector. Quantum computing is maturing, after long being considered a niche market relying on a yet-to-be-proven technology. Companies in the space are now promising to unlock business value in the coming years, attracting more customer interest and plenty of investor money. OQC’s round was led by Bullhound Capital, with participation from the British Business Bank, alongside European investors Fynveur, Cofides, Fulcrum Asset Management, Pentland Ventures, Magdalen College Oxford, Oxford Capital and Firgun. US investment firms Alpha Edison and 18 West, as well as Singapore’s Adaptive Capital Partners also participated. What does OQC do? OQC builds quantum computers using superconducting qubits. This means it uses electrons to create qubits, or quantum bits, which are the tiny particles forming the basis of quantum computers. Superconducting qubits are the approach adopted by major players in the space, including US tech giants IBM and Google, as well as Finnish company IQM, which recently announced plans to list on Nasdaq at a $1.8bn valuation. OQC has also built a platform to enable customers to access its quantum computers “as a service", which means the scaleup deploys quantum systems in partner data centres like US-based Equinix and Digital Realty. These partners in turn offer access to the systems via the cloud, or enable users to run their workloads