Human papillomavirus (HPV) is a well-established etiologic factor in oropharyngeal squamous cell carcinoma, but its role in oral tongue squamous cell carcinoma (OTSCC) and patterns of recurrence is less clearly defined. A 54-year-old former smoker with multiple comorbidities had HPV-positive pT2N0M0 squamous cell carcinoma of the left lateral tongue and floor of mouth resected in 2022 with partial glossectomy, floor-of-mouth resection, and elective neck dissection, without adjuvant therapy. He remained disease-free following revision tongue debulking for dysplasia in 2024. In February 2026, he presented with a one-month history of a painful right ventral tongue mass impairing oral intake. Examination revealed a 2.5-cm friable exophytic lesion on the right ventral tongue without palpable cervical lymphadenopathy. Punch biopsy demonstrated invasive moderately differentiated squamous cell carcinoma. PET/CT showed an intensely hypermetabolic right tongue lesion with suspicious ipsilateral cervical lymph nodes but no distant metastases; an incidental focus of sigmoid colon uptake was noted. A multidisciplinary tumor board considered the new lesion a metachronous contralateral OTSCC in the setting of prior extensive left tongue surgery and recommended induction chemoimmunotherapy with pembrolizumab, docetaxel, and cisplatin, followed by restaging and reassessment for further surgery or radiotherapy. The patient completed the first cycle with manageable toxicity and preserved oral intake; response assessment after two cycles is pending. This case illustrates metachronous contralateral OTSCC in an HPV-associated setting despite guideline-concordant initial management and highlights the emerging role of induction chemoimmunotherapy as a function-preserving strategy in locally advanced recurrent oral cavity cancer after prior major tongue resection.