Singtel Optus Pty Limited is a major Australian telecommunications company headquartered in Macquarie Park, Sydney. Optus is the second-largest telecommunications company in Australia, with over 10.7 million mobile customers and 1.3 million home customers as of 2025. Its mobile network covers 99.11% of the Australian population as of 2026, with plans to cover all of Australia by 2026 through its partnership with SpaceX.