Severe cases of heart failure (HF), both new onsets of HF and acute exacerbations of chronic HF, are frequently observed during infections. A potentially lethal complication of HF with very low left ventricular ejection fraction is thrombus formation within the heart chambers. A 67-year-old male was admitted to our hospital with shortness of breath after a COVID-19 infection. He was diagnosed with severe acute heart failure and a massive thrombus in the left ventricle. While the thrombus subsided quickly without any observable embolic events, the patient had a lengthy hospitalization stay complicated by tachyarrhythmias and secondary infections. Eventually, his heart failure improved, and he continued to recover post-hospital discharge. We present a case of severe heart failure and intraventricular thrombosis following COVID-19 infection. The patient required potent anti-inflammatory medication in addition to conventional heart failure medication to recover from his HF.