Globally, tuberculosis (TB) testing and treatment have declined dramatically during the COVID-19 pandemic. We quantified the change in TB visits, testing, and treatment compared with a 12-month pre-pandemic baseline at the national referral hospital's TB Clinic in Lusaka, Zambia, in the first year of the pandemic. We stratified the results into early and later pandemic periods. In the first 2 months of the pandemic, the mean number of monthly TB clinic visits, prescriptions, and positive TB polymerase chain reaction (PCR) tests decreased as follow: -94.1% (95% CI: -119.4 to -68.8%), -71.4% (95% CI: -80.4 to -62.4%), and -73% (95% CI: -95.5 to -51.3%), respectively. TB testing and treatment counts rebounded in the subsequent 10 months, although the number of prescriptions and TB-PCR tests performed remained significantly lower than pre-pandemic. The COVID-19 pandemic significantly disrupted TB care in Zambia, which could have long-lasting impacts on TB transmission and mortality. Future pandemic preparedness planning should incorporate strategies developed over the course of this pandemic to safeguard consistent, comprehensive TB care.