The heat capacity morphology of potassium n-hexanoate from T = 6 K to T = 350 K was determined by equilibrium adiabatic calorimetry and by differential scanning calorimetry (d.s.c.) from T = 300 K to T = 635 K. The curve was characterized by peaks assumed to be associated with solid --> solid first order transformations at about T = 252.5 K and T = 325 K. A much sharper transition, also considered to be first order was observed at T = 497 K. Fusion was observed at T = 548 K. Tabulated experimental molar heat capacities and adjuvant smoothed thermodynamic functions derived by integration therefrom are presented at selected temperatures.