Ti-B-C nanocomposite coatings with varied carbon content were deposited by dual pulsed magnetron sputtering of TiB 2 and graphite targets at substrate temperatures of ≤70 °C (no heating) and 400 °C. The effects of carbon content and substrate temperature on the coatings' microstructure, phase composition, mechanical properties, and tribological performance were systematically examined. X-ray diffraction revealed that all Ti-B-C coatings were X-ray amorphous, while transmission electron microscopy identified nanocrystalline TiB x grains (4–7 nm) embedded in an amorphous matrix at low carbon levels, transitioning to finer grains (2–3 nm) and increased structural disorder with higher carbon incorporation. Energy-dispersive spectroscopy confirmed a monotonic increase in carbon content with rising graphite target power. Surface morphology evolved from smooth and dense to increasingly textured with elevated carbon content and substrate heating, reflecting enhanced atomic mobility. Nanoindentation measurements showed a reduction in hardness with increasing carbon content. Although higher carbon levels in Ti-B-C coatings tend to lower the coefficient of friction, they can concurrently result in elevated wear rates. Wear track and counterbody analyses confirm that higher carbon content also suppresses adhesive transfer and mitigates counterbody wear. These findings demonstrate the capability of dual pulsed magnetron sputtering to tailor Ti-B-C coatings with optimized mechanical and tribological properties for advanced engineering applications.