This study investigated the influence of increased ionic strength (I) induced by addition of NaCl (80–580 mM) to pasteurised skim milk minerals partitioning, casein micelle properties and β-casein partitioning as a function of temperatures (i.e., 4, 10, 25, and 55 °C). Increasing I influenced the partition of divalent minerals in serum phase, especially total and ionic calcium concentration in the serum phase, while it had no effect on monovalent mineral partitioning. pH significantly decreased with increasing I due to changes in mineral equilibria, and increased protein content in the milk serum phase, especially at low temperatures. The average particle size and net zeta-potential decreased with increasing I most pronounced at 25 and 55 °C. The results obtained in this study provide new insights into mineral and protein partitioning of milk as influenced by ionic strength relevant for control of mineral distribution and for the development of new dairy products.