The leading luxembourg quantum computing companies and institutions in 2026 form an infrastructure-led ecosystem, organised around national computing and communication infrastructure rather than around startups. Luxembourg is small, but it is building serious quantum infrastructure: a national quantum computer, a leading role in European satellite quantum communication, and a national quantum-communication network. Ten organisations define the luxembourg quantum computing companies landscape in this guide: SES, LuxProvide, MeluXina-Q, the University of Luxembourg, SnT, LIST, LuxQCI, LuxTrust, itrust consulting, and LuxConnect. Why Luxembourg’s quantum ecosystem is infrastructure-led Luxembourg’s quantum landscape is infrastructure-led, and it is important to be clear about that. The country does not have a set of homegrown venture-funded quantum-hardware or quantum-software startups. The luxembourg quantum computing companies landscape is built instead from national infrastructure: a national high-performance-computing operator, a satellite company, a national quantum-communication programme, and the research institutions and trust providers around them. What makes Luxembourg distinctive is the scale and ambition of that infrastructure relative to the country’s size. Luxembourg is hosting a national quantum computer through the European high-performance-computing initiative, the Luxembourg satellite operator SES is leading Europe’s first quantum-communication satellite project, and the country has a national quantum-communication network on the ground. The luxembourg quantum computing companies landscape is therefore a small but well-resourced, infrastructure-led ecosystem, using national assets to build quantum capability quickly. A national quantum computer and a satellite Two pieces of infrastructure define the luxembourg quantum computing companies ecosystem. The first is MeluXina-Q, Luxembourg’s first quantum computer, a machine selected under the European high-performance-computing initiative and planned to be hosted by the national computing operator LuxProvide from 2026. It is reported to begin as a small silicon-spin-qubit processor, integrated with the MeluXina supercomputer so that researchers can run hybrid quantum-classical workloads. The second is EAGLE-1, a project led by the Luxembourg satellite