Theremoreflectance techniques that utilize a fiber-based probe have obvious advantages for characterizing the thermal properties of liquids and biological materials. For instance, an all-fiber thermoreflectance system would allow for its integration into advanced microscope facilities to characterize the local thermal properties of biological materials. However, it is unclear to what extent the probe itself is sensitive to material thermal properties, particularly as the thermal conductance between the transducer and the contacting material is changed by orders of magnitude. The impacts of the transducer’s thermal properties, the fiber’s mode field diameter, and fiber cladding thickness on measurement sensitivity are also not well understood. In this paper, I develop a numerical model to evaluate the sensitivity of a fiber-based thermoreflectance probe when used to characterize the thermal properties of materials with Frequency-domain thermoreflectance (FDTR).