PURPOSE: Evidence supporting social media-based recruitment of cancer survivors is limited. This paper describes how we used Facebook during the COVID-19 pandemic to augment our recruitment of breast cancer survivors for our two-site telephone-based randomized clinical trial (RCT) at Dartmouth-Hitchcock Medical Center and the University of Alabama at Birmingham. METHODS: Originally a two-site RCT of a telephone-delivered breast cancer survivorship intervention, we extended our clinic-based recruitment to Facebook. Participant characteristics, geographic reach, and baseline outcomes were compared across recruitment sources (ie, two clinics and Facebook) using descriptive statistics and effect sizes. RESULTS: Enrollment rates (20%-29%) were comparable across recruitment sources. The 21-month Facebook marketing campaign accounted for 59% (n = 179/303) of our total sample and had the greatest geographic reach, recruiting women from 24 states. The Facebook campaign reached a total of 51,787 unique individuals and cost $88.44 in US dollars (USD) per enrolled participant. Clinic samples had a greater proportion of women who were widowed (8% v 1%; P = .03) and Facebook had a higher proportion of women with a household income over $40,000 USD (83% v 71%; P = .02). There were no statistically significant differences between Facebook and the two clinics on baseline survey scores. CONCLUSION: Augmenting traditional recruitment with Facebook increased our RCT's geographic and sociodemographic reach and supported meeting recruitment goals in a timely way. In the wake of the COVID-19 pandemic, cancer survivorship researchers should consider using social media as a recruitment strategy while weighing the advantages and potential biases introduced through such strategies.