Antimony (Sb) has emerged as an attractive anode material for both lithium and sodium ion batteries due to its high theoretical capacity of 660 mA h g−1. In this work, a novel peapod-like N-doped carbon hollow nanotube encapsulated Sb nanorod composite, the so-called nanorod-in-nanotube structured Sb@N-C, via a bottom-up confinement approach is designed and fabricated. The N-doped-carbon coating and thermal-reduction process is monitored by in situ high-temperature X-ray diffraction characterization. Due to its advanced structural merits, such as sufficient N-doping, 1D conductive carbon coating, and substantial inner void space, the Sb@N-C demonstrates superior lithium/sodium storage performance. For lithium storage, the Sb@N-C exhibits a high reversible capacity (650.8 mA h g−1 at 0.2 A g−1), excellent long-term cycling stability (a capacity decay of only 0.022% per cycle for 3000 cycles at 2 A g−1), and ultrahigh rate capability (343.3 mA h g−1 at 20 A g−1). For sodium storage, the Sb@N-C nanocomposite displays the best long-term cycle performance among the reported Sb-based anode materials (a capacity of 345.6 mA h g−1 after 3000 cycles at 2 A g−1) and an impressive rate capability of up to 10 A g−1. The results demonstrate that the Sb@N-C nanocomposite is a promising anode material for high-performance lithium/sodium storage.