The most common sites of metastasis from breast cancer are the bone, lungs, and liver. Metastasis to uterine leiomyomas from breast cancer is extremely rare, and here we present such a case. A 46-year-old premenopausal lady presented with a left breast lump, diagnosed as cT4bN2M0 invasive ductal carcinoma. Imaging revealed a large asymptomatic subserosal uterine fibroid with no signs of metastasis elsewhere. She received neoadjuvant chemotherapy and underwent modified radical mastectomy with total abdominal hysterectomy and bilateral salpingo-oophorectomy. Histopathology showed metastatic breast carcinoma within the leiomyoma, confirmed by GATA3 positivity and morphological similarity to the breast tumor. The ovaries, fallopian tubes, and cervix were free of disease. This case underscores the importance of thorough histopathological evaluation of surgical specimens, even without preoperative suspicion of metastasis.