Zirconolite (CaZrTi2O7) has been proposed as a host phase for excess weapons plutonium. and the standard molar entropy Delta(0)(298.15 K) S-m(o) and other derived thermodynamic functions are needed to describe it completely. The heat capacity of CaZrTi2O7 has been measured from T approximate to 20 K to T approximate to 400 K with an adiabatic calorimeter. A six-term fitting equation based on Debye and Einstein functions has been shown to represent the heat capacity over the entire range of temperature to within the experimental uncertainty. This equation has been used to calculate the thermodynamic functions to T = 400 K and to extrapolate these functions to T = 1500 K. In particular, Delta(0)(298.15 K)S(m)(o) for CaZrTi2O7 is 193.3 J . K-1 . mol(-1).