The objective of this work was to determine the effects of whey composition on the physicochemical properties of whey butter and compare with milk butter based on these properties. Whey samples were obtained from the whey processing plants located in different regions of Turkey. Whey composition influenced the major and minor components of whey butters. Differences among the whey butters were observed on titratable acidy (TA, 0.43-0.55%), acid value (AV, 0.75-0.90 mg KOH/g), moisture (17.33-19.05%), fat (80.23-81.47%), nonfat solid (0.66-1.20%), NaCl (0.10-0.23%), peroxide value (PV, 1.08-1.50 meq O 2 /kg), total carotenoids (1.78-2.21 mg/kg), γand total tocopherols (1.06-1.41 and 27.02-27.33 mg/kg, respectively), Ca (73.12-94.72 mg/kg), P (56.03-72.20 mg/kg), K (73.36-140.10 mg/kg), Mg (12.83-18.12 mg/kg), Na (63.95-165.85 mg/kg), total minerals (283.32-485.53 mg/kg), colour (L * , 86.46-89.52 and b * , 12.21-15.52) and certain fatty acids. The milk butters were one-to threefold lower in TA, AV, moisture, NaCl and PV and one-to 3.4-fold higher in fat, nonfat solids, protein, total carotenoids, α-, γand total tocopherols, Ca, P, K, Mg and total minerals. Whey butters were distinctly brighter and less yellower. Butter source had no effect on iodine value (35.39 AE 0.15 g I 2 /100 g), saponification value (225.22 AE 0.17 mg KOH/g), β-tocopherol (0.41 AE 0.02 mg/kg), certain fatty acids, melting characteristic and thermo-oxidative stability. The cluster analysis enabled the division of whey and milk butters into two separate groups. These results highlighted that partial transfer of certain compounds from milk to whey during cheese manufacturing and biochemical and chemical changes such as lipolysis, hydrolysis and oxidation that occur in the period from the whey production to butter processing were largely responsible for the differences in the whey and milk butter properties.