The Gibbs energy of formation of Ho₂Ru₂O₇(s) has been determined by employing a solid-state electrochemical cell incorporating an oxide ion conducting electrolyte. The reversible electromotive force (e.m.f.) of the following cell has been measured: cell: ()Pt/{Ho₂O₃(s) + Ho₂Ru₂O₇(s) + Ru(s)}//CSZ//O₂(p(O₂)=21.21 kPa)/Pt(+). The Gibbs energy of formation of Ho₂Ru₂O₇(s) from elements in their standard state, calculated by the least squares regression analysis of the data obtained in the present study, can be given by: {Δ_fG°(Ho₂Ru₂O₇,s)/(kJ mol^-1)±2.6}=-2518.6 + 0.6225(T/K); (937≤T/K≤1265).The standard molar heat capacity C°_p,m(T) of Ho₂Ru₂O₇(s), was measured using a heat flux type differential scanning calorimeter (DSC) in the temperature range from 307 K to 765 K. The heat capacity was fitted into a mathematical expression and can be represented by: C°_p,m((Ho₂Ru₂O₇,s,T)(JK^-1mol^-1))=289.8 +3.06X10^-2T(K)-33.74X10⁵/T²(K); (307≤T(K)≤765). The heat capacity data of Ho₂Ru₂O₇(s), alongwith the data obtained from the oxide electrochemical cell were used to calculate the standard enthalpy of formation and absolute molar entropy of the compound.