Abstract <p>High entropy alloys are of significant interest as promising materials, particularly in the energy sector, where thermophysical properties are of key importance. This study presents an analysis of the thermophysical properties (coefficient of thermal expansion, thermal diffusivity, specific heat capacity, and thermal conductivity) of single-phase Co₄₀Cr₂₀Fe₂₅Ni₁₅, Co₄₀Cr₂₅Fe₂₀Ni₁₅, Co₂₅Cr₂₀Fe₂₅Ni₃₀, Co₂₅Cr₂₅Fe₂₀Ni₃₀, and Co₂₅Cr₂₀Fe₂₀Ni₃₅ alloys within the temperature range of 300 to 1173 K. The thermophysical characteristics of the Co–Cr–Fe–Ni alloys show no pronounced dependence on composition up to 800 K. However, upon further heating in the range of 773–1023 K, anomalies are observed: a stepwise increase in heat capacity and the coefficient of thermal expansion, as well as non-monotonic changes in thermal diffusivity and thermal conductivity. The primary heat transfer mechanism in these high entropy alloys is electronic conduction, which allows them to be classified as high-resistivity metallic conductors.</p>