The main disadvantage of using transition metal oxides for Na+-ion batteries is the sluggish kinetics of insertion of Na+ ions into the structure. Here, we introduce nanosized anatase TiO2 that is partially doped with fluorine (TiO2−δ F δ ) to form electro-conducting trivalent Ti3+ as an ultrafast Na+ insertion material for use as an anode for sodium-ion batteries. In addition, the F-doped TiO2−δ F δ is modified by electro-conducting carbon nanotubes (CNTs) to further enhance the electric conductivity. The composite F-doped TiO2 embedded in CNTs is produced in a one-pot hydrothermal reaction. X-ray diffraction and microscopic studies revealed that nanocrystalline anatase-type TiO2−δ F δ particles, in which fluorine is present with TiO2 particles, are loaded on the CNTs. This yields a high electric conductivity of approximately 5.8Scm−1. The first discharge capacity of the F-doped TiO2 embedded in CNTs is approximately 250mAh (g-oxide)−1, and is retained at 97% after 100 cycles. As expected, a high-rate performance was achieved even at the 100C discharging rate (25Ag−1) where the composite material demonstrated a capacity of 118mAhg−1 under the 0.1C-rate charge condition. The present work also highlights a significant improvement in the insertion and extraction of Na+ ions when the material was charged and discharged under the same rate of 35C (8.75Ag−1), delivering approximately 90mAh (g-oxide)−1.