Head & neck cancers (HNC) & their treatments impact health-related quality of life (HRQL) by affecting functions. While clinical factors (primary tumour site, radiation volume & treatment modality) may influence outcomes, the relationship between age & long-term HRQL remains unclear. This study evaluated the impact of age on HRQL among people treated for HNC with radiation therapy (RT). Patients (≥18 years) with HNC, receiving curative RT (definitive & adjuvant) between December 2020 & December 2025 at Westmead & Blacktown Hospitals had their routinely collected HRQL data (EORTC QLQ-C30 & QLQ-HN35) grouped into 11 survivorship timepoints, stratified by age (<70 vs ≥70). Analysis included Pearson’s correlation, t-tests, & multivariate general linear modelling to evaluate the effects of age, primary site, RT volume (primary only, primary + ipsilateral nodes, primary + bilateral nodes), treatment modality (RT, chemoradiotherapy, surgery + RT ± chemotherapy) on HRQL. Of 252 respondents (median age 65 & range 24-91), 73% were male. Age & global HRQL showed a weak negative correlation (r=-0.112, p=0.013), though mean global HRQL did not significantly differ between age groups. Older people reported significantly better emotional (p=0.007) & social functioning (p=0.23) & less financial toxicity (p=0.025). Conversely, younger people reported greater symptom burden in speech (p=0.003), social eating (p=0.026), mouth opening (p=0.030), sticky saliva (p=0.019) & cough (p=0.004). On multivariate analyses, RT volume (primary + bilateral nodes) was significantly associated with swallowing, social eating & sticky saliva (all p<0.001). Primary site influenced social eating (oral cavity & salivary gland; p=0.010) & sexuality outcomes (advanced larynx, hypopharynx & oral cavity; p<0.001). Older patients treated curatively did not appear to have worse HRQL in their survivorship compared to younger patients. The younger survivors reported greater symptom burden across many domains.