This study examined associations between HPV status and weight change in oropharyngeal cancer (OPC). OPC patients receiving concurrent chemoradiotherapy in Toronto, Canada were included. Relationships were assessed between HPV status and weight loss grade (WLG, combining weight loss and current body mass index); weight change during treatment; and HPV status and WLG/weight change on overall (OS) and cancer-specific (CSS) survival. Of 717 patients, WLG pre-radiation was less severe among HPV-positive compared to HPV-negative, though weight loss during treatment was greater. The adjusted odds ratio for greater WLG among HPV-positive versus HPV-negative was 0.47 (95%CI 0.28-0.78). Grade-4 WLG (worst category) experienced poorer OS and CSS (OS adjusted hazard ratio (aHR) 4.08; 95%CI 1.48-11.2, compared to Grade-0); and was non-significant for HPV-negative (aHR 2.34; 95%CI 0.69-7.95). Relationships between weight change before/during treatment and survival had similar direction between HPV-positive and HPV-negative, but of greater magnitude in HPV-positive patients.