This article presents a comprehensive analysis of the thermal properties and distributed temperature-sensing responses of nanoparticles (NPs)-doped optical fiber using optical frequency-domain reflectometry (OFDR). The thermomechanical analysis (TMA) for the NP-doped fiber is performed to evaluate the thermal expansion coefficient of such fibers and their differences compared with standard telecom optical fibers (SMFs). In addition, the thermo-optical coefficient of such fibers is analyzed as a function of their steady-state temperature responses, whereas the thermal conductivity is assessed from the transient thermal analysis of the NP-doped fiber. The results in distributed temperature measurement indicate better sensing performance of NP-doped fiber, which has 2.6 times higher temperature sensitivity, a smaller response time, and high accuracy estimated from a determination coefficient (R2) of 0.993 and root mean squared error (RMSE) of 1.28 ∘ C. Therefore, the main findings of this work indicate the influence of the NPs composition on the thermal properties of the optical fibers, where the addition of oxide particles (in conjunction with the changes in the glass matrix) presented a positive effect on the distributed temperature sensing capabilities with a thermal expansion coefficient increase of 30% and thermal conductivity increase of 25% when compared with SMF. Thus, this article provides not only the comparison of the temperature sensing performance of an NP-doped fiber but also a straightforward method for the assessment of distributed physical parameters of the fiber that can be used for any specialty optical fiber, which can also be used as a nondestructive method for the assessment of the optical fiber composition.