Purpose: Australia’s population is ageing, with those aged ≥80 years expected to triple by 2050. Comprehensive, longitudinal data on surgical volume and outcomes in this group remain limited. This study reports changes in surgical volume and outcomes in adults aged ≥80 years compared to those aged 20-79 years between 2009 and 2019 in Victoria. Methodology: This retrospective observational study examined adult surgical admissions from the Victorian Admitted Episodes Dataset. Extracted variables included volume, patient demographics, hospital type and perioperative outcomes (30-day mortality, 1-year mortality, in-hospital complications, and blood transfusions). χ2 tests were used to compare differences between age groups and time points. Results: 1,800,274 adult surgical episodes were identified with a 34% increase in volume from 2009 to 2019. The ≥80 years cohort made up 9.6% of all admissions in both years. Combining both years, the ≥80 years cohort had higher 30-day mortality (1.6% vs 0.3%, p < 0.001), 1-year mortality (9.5% vs 1.6%, p < 0.001), and complication rates (15.7% vs 11.3%, p < 0.001) compared to the 20-79 cohort. Blood transfusion rates declined in both groups. Despite improved complication rates (17.8% to 15.7%, p < 0.001), 1-year mortality increased (8.7% to 9.5%, p < 0.001) in the ≥80-year cohort. Conclusion: The proportion of adult surgical admissions in Victoria attributable to patients aged ≥80 years did not increase significantly from 2009 to 2019. Exploration of trends among the 65–79 age group may yield the effects of the ageing population. Further investigation is warranted to identify the drivers of increased 1-year mortality in the ≥80-year cohort.