Thrombotic thrombocytopenic purpura (TTP) is a rare disease characterized by thrombocytopenia, microangiopathic hemolytic anemia, and ischemic organ damage. Several cases of TTP associated with administration of COVID-19 vaccines have been reported. We report a case of a 63-year-old woman with a past medical history of hypertension, diabetes mellitus, chronic kidney disease, HIV infection, and remote history of TTP who presented with several days of shortness of breath on exertion, chest tightness, low-grade fever, and bruising thirty-three days after receiving the second dose of the mRNA-1273 COVID-19 vaccine. Thrombocytopenia and hemolytic anemia with schistocytes were noted on testing, and ADAMTS13 activity was <5%. Temporizing treatment with fresh frozen plasma was started immediately on presentation, and treatment was continued with daily therapeutic plasma exchange and corticosteroids. TTP should be considered in patients who present with thrombocytopenia after COVID-19 vaccination, especially if there is a past history of TTP.