Research on oleogels has a health and sustainability imperative for reducing saturated-fat intake. Herein, the physicochemical properties of whey protein aggregates (WPA) with α-lactalbumin (α-La) addition (5-10 %), ultrasonication (1-2 min), and heating process (85-95 °C), and consequently, the functional characteristics of WPA-based oleogels (WPO) and their potential for replacing commercial butter were investigated. More α-La incorporation and longer ultrasonication increased the hydrogen bonding and β-sheet (34 %-50 %), while reduced random coil of WPA (27 %-11 %), which promoted WPA formation, increased WPA structural density, and led to a decline in particle size of WPA driven by surface hydrophobicity decrease. Therefore, the WPO exhibited excellent oil-holding capacity, thermal stability, viscoelasticity and spreadability. WPO consisted of 95 °C-heated WPA with 5 % α-La addition or 1 min-ultrasonication showed textural and rheological behavior similar to butter. These results contribute to the formulation of whey protein oleogels with controlled physicochemical and functional properties, showing potential being applied as fat substitutes.