COVID-19 has posed a serious threat to people worldwide, especially the older adults, since its discovery. Tai Chi as a traditional Chinese exercisethat belongs to traditional Chinese medicine has proven its effectiveness against COVID-19. However, no high-quality evidence is found on the dose-response relationships between Tai Chi and clinical outcomes in patients with COVID-19. This study will evaluate and determine the clinical evidence of Tai Chi as a treatment in elderly patients with COVID-19.The following electronic bibliographical databases including PubMed, EMBASE, Web of Science, Cochrane Library, China National Knowledge Infrastructure, VIP Database and Wanfang Database will be screened from their inception date to 30 June 2022. All eligible randomised controlled trials or controlled clinical trials related to Tai Chi for elderly patients with COVID-19 will be included. The primary outcomes are forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC) and FEV1/FVC ratio (FEV1%). The secondary outcomes are the time of main symptoms disappearance, length of hospital stay, serum levels of interleukin (IL)-6, IL-1b and tumour necrosis factor-α, and adverse event rate. Two independent reviewers will select the studies, extract the data, and analyse them on EndNote V.X9.0 and Stata V.12.1. The robust error meta-regression model will be used to establish the dose-response relationships between Tai Chi and clinical outcomes. The heterogeneity and variability will be analysed by I2 and τ2 statistics. Risk of bias, subgroup analysis and sensitivity analysis will also be performed. The quality of evidence will be assessed by the Grading of Recommendations Assessment, Development and Evaluation, and the risk of bias will be evaluated by using the Physiotherapy Evidence Database Scale.This study will review published data; thus, obtaining ethical approval and consent is unnecessary. The results will be disseminated through peer-reviewed publications.CRD42022327694.© Author(s) (or their employer(s)) 2022. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.