This article introduces a weight function method for fracture analysis of a circumferentially cracked functionally graded hollow cylinder subjected to thermal loads. The non-Fourier hyperbolic heat conduction model is used to determine the transient temperature distribution in the functionally graded cylinder. Solutions for transient temperature and stress distributions in the uncracked cylinder are derived by converting the governing differential equations into Fredholm integral equations in the Laplace domain. A numerical Laplace inversion technique is used to calculate the wave-like temperature and stress solutions in the time domain. These solutions are utilized to determine stresses acting on the faces of the circumferential crack in the local perturbation problem. A weight function technique is developed to compute the corresponding mode I thermal stress intensity factors. Comparisons to the results generated by finite difference and finite element methods demonstrate the high level of accuracy attained by the application of the developed procedures. Further parametric analyses are presented to illustrate the influences of dimensionless time, crack depth to thickness ratio, power law index, and thermal relaxation time upon the stress intensity factors.