In this study, F-doped SnO₂ (FTO) thin films were deposited on glass substrates using ultrasonic spray pyrolysis at a substrate temperature of 400 °C, and then they were annealed at various temperatures (T_a) of 350–475 °C. The structural, morphological and magnetotransport properties of the FTO films were studied. The FTO films exhibited tetragonal structure with preferred orientations of (110), (200), and (211), and polycrystalline morphology. In addition, all the FTO films possessed negative magnetoresistance (MR) in low temperature (T) range of 2 – 10 K under the perpendicular field of ± 1 T. We employed weak localization (WL) theory to analyze MR data, and consequently T-dependent coherent length L_ϕ was achieved. The L_ϕ decays with T by the power law, L_ϕ ~ T^-p. We found that the coefficient p decreased with increasing T_a, attributing to the inhomogeneous state and energy-transfer strength via electron-electron (e-e) and electron-phonon (e-ph) scattering processes of the samples. The origin of negative MR is due to the weak localization and electron-electron interaction.