The aim of this study was to characterise milk fat from whey butter and to identify potential differences between whey butter (WB) and sweet cream butter (milk butter – MB). The fatty acid (FA) profile, thermal properties, colour parameters, texture properties, and sensory attributes of MB and WB were compared. The values of texture properties (firmness, brittleness, and cohesiveness) and colour parameters (values of b* and the yellowness index) of WB were lower than MB. The sensory analysis showed lower values of consistency descriptors (firmness, brittleness, cohesiveness), a less intense nutty and milky aroma, and a more intense cheesy aroma and taste in WB than in MB. WB was more abundant in monounsaturated, polyunsaturated, and long-chain FAs, including C18:0, C18:1 Σt, C18:1 Σc, C18:2, C18:3, and C18:2 c9, t11, and it was less abundant in saturated and medium-chain FAs, including C10:0, C12:0, C14:0, C14:1, C15:0, C16:0, and C16:1, relative to MB. Water content (MB vs WB and the corresponding fats) and thermal history (single vs repeated heating and cooling treatments) affected differential scanning calorimetry curves and phase transition peaks. The principal component analysis revealed that the FA profile influenced the crystallisation and melting peaks of MB fat (MBF) and WB fat (WBF). WBF crystallisation occurred at a lower temperature, was characterised by lower enthalpy, and proceeded more rapidly than MBF crystallisation. Various fat fractions had different melting characteristics, and most WBF fractions were characterised by lower melting enthalpy and a smaller maximum difference in heat flow than MBF. Whey butter and milk butter differed in physicochemical properties and sensory attributes, and their thermal profiles depended on the FA profile, water content, and thermal history.