The COVID-19 pandemic has impacted a wide range of health services. This study aimed to quantify the impact of the COVID-19 pandemic on manual therapy service utilization within the Australian private healthcare setting during the first half of 2020. Quarterly data regarding the number and total cost of services provided were extracted for each manual therapy profession (i.e., chiropractic, osteopathy, and physiotherapy) for the period January 2015 to June 2020 from the Australian Prudential Regulation Authority. Time series forecasting methods were used to estimate absolute and relative differences between the forecasted and observed values of service utilization. An estimated 1.3 million (13.2%) fewer manual therapy services, with a total cost of AUD 84 million, were provided within the Australian private healthcare setting during the first half of 2020. Reduction in service utilization was considerably larger in the second quarter (21.7%) than in the first quarter (5.7%), and was larger in physiotherapy (20.6%) and osteopathy (12.7%) than in chiropractic (5.2%). The impact varied across states and territories, with the largest reductions in service utilization observed in New South Wales (17.5%), Australian Capital Territory (16.3%), and Victoria (16.2%). The COVID-19 pandemic has had a profound impact on manual therapy service utilization in Australia. The magnitude of the decline in service utilization varied considerably across professions and locations. The long-term consequences of this decline in manual therapy utilization remain to be determined.