The correlation between dielectric relaxation and conduction mechanisms in the Ba0.9La0.1Fe12O19 ceramic hexaferrite, at temperatures below 100K was investigated. The sample was prepared using the conventional solid-state reaction method. X-ray diffraction analysis indicated that the sample is composed of a hexagonal BaFe12O19 phase (lattice parameters a = 5.8778(6) Å and c = 23.170(3) Å) and a small proportion of hematite (α-Fe2O3). The average grain size is 1.48 ± 0.4 μm, with irregular hexagonal and agglomerated grains. The magnetic hysteresis curve shows characteristics typical of ferro and ferrimagnetic materials, with an effective magnetic anisotropy coefficient of 0.960×106emu/cm3 and an anisotropy field of 1.587×104Oe. A dielectric relaxation process is observed between 50 and 100K, with an activation energy of 60.4 ± 0.4meV and a characteristic relaxation time of 2.09 ×10-10s, mainly attributed to the electrical behavior of the grains. Two conduction mechanisms were identified: small polaron tunneling (high temperatures and low frequencies) and correlated barrier hopping of electrons (low temperatures and high frequencies). The activation energy for free polaron formation, according to the Komine-Iguchi hopping polarization model, was 7.12 ± 0.02meV. In the dielectric modulus relaxation process between 30 and 54K, the activation energy was 40.8 ± 0.9meV, with a characteristic relaxation time of 2.41×10-10s. The small polaron conductivity in the grain region was 67.52meV and 54.0meV in the grain boundary region. The results highlight that the polarization and conduction mechanisms in this ceramic at low temperatures are dominated by small polaron hopping and tunneling, and emphasize the influence of La3+ doping on the structural, magnetic, and electrical properties of barium hexaferrite.