Silicon Quantum Computing (SQC) is an Australian quantum hardware company building a commercial-scale, error-corrected silicon-based quantum computer using an atomically precise approach to silicon fabrication. Founded in 2017 by Prof. Michelle Simmons, the 2018 Australian of the Year, the company spun out of UNSW Sydney as Australia's first quantum computing company, backed at incorporation by roughly A$83 million from the Australian federal government, the New South Wales government, UNSW, Telstra, and the Commonwealth Bank of Australia.

SQC's distinguishing capability is the manufacture of pristine silicon-spin qubits by placing individual phosphorus atoms within isotopically pure silicon using scanning tunnelling microscopes. Simmons pioneered this atomic-precision technique, accurate to 0.13 nanometres (world-leading), over 25+ years. The approach uses the nuclear and electron spins of these atoms as qubits, which have demonstrated long coherence times and world-leading fidelity metrics. Operating as a full-stack company with in-house QPU manufacturing, SQC can design, produce, and test new quantum chips in under a week, and already supplies commercial products, including its Watermelon™ and Quantum Twins™ offerings, to enterprise and government customers.

Headquartered in Sydney and chaired by former Arm CEO Simon Segars, SQC is one of eleven companies to advance to Stage B of DARPA's Quantum Benchmarking Initiative, possessing immense sovereign strategic value. Its investor base includes Australia's National Reconstruction Fund Corporation, UNSW, and Telstra, and in June 2026 the company secured fresh capital from the NRFC..