The 23-year-old Spaniard arrived in Vienna on the back of titles in Doha and Tokyo and completed a perfect 16-0 record at ATP 500 events in 2026, capping another dominant week without dropping a set across his five matches.
Alcaraz seized control from the opening stages, breaking De Minaur's serve in the first game and quickly establishing a double-break advantage as the Australian struggled to contain the world number two's intensity.
The seven-time Grand Slam champion raced through the opening set 6-1, repeatedly punishing short balls and forcing errors from De Minaur.
Although the 27-year-old Australian put up greater resistance in the second set and kept pace for long spells, Alcaraz delivered a high-quality all-court performance to close out victory in 97 minutes and secure his seventh consecutive win over De Minaur.
Alcaraz will head to next week's Paris Masters brimming with confidence after his flying start to the European indoor swing, having already qualified for the season-ending ATP Finals in Turin.
De Minaur, meanwhile, will turn his attention to Paris as he continues his push to qualify for the ATP Finals for a third consecutive year.