Ovarian vein thrombosis (OVT) is a rare but potentially life-threatening complication that is usually seen in the intrapartum or postpartum period but can also be seen in patients with risk factors for venous thromboembolism. When symptomatic, it usually presents with abdominal pain and other vague constitutional symptoms, hence it is important for healthcare professionals to be aware of this condition when evaluating patients with risk factors. We present a rare case of OVT in a patient with breast cancer. Due to a lack of clear guidelines regarding the treatment and duration of treatment in non-pregnancy-related OVT, we followed the guidelines for the treatment of venous thromboembolism and started the patient on rivaroxaban for a three-month duration with close outpatient follow-up.