A simple and inexpensive automated method for determining the thermal conductivity of a combinatorial library of thin films is demonstrated by measuring the thermal conductivity of a sputtered silicon dioxide film of varying thickness deposited on single crystal silicon. Using 3ω measurements, two methods for calculating the substrate thermal conductivity and two methods for determining the film thermal conductivity are demonstrated and compared. The substrate thermal conductivity was found to be 139 ± 3 W/m·K. Using the measured variation in film thickness, the film thermal conductivity was found to be 1.11 ± 0.05 W/m·K, in excellent agreement with published values for sputtered SiO2, demonstrating the accuracy of the method.