As a typical two-dimensional transition metal dichalcogenide, molybdenum disulfide (MoS2) is considered a potential anode material for sodium-ion batteries (NIBs), due to its relatively high theoretical capacity (~ 670 mAh·g–1). However, the low electrical conductivity of MoS2 and its dramatic volume change during charge/discharge lead to severe capacity degradation and poor cycling stability. In this work, we developed a facile, scalable, and effective synthesis method to embed nanosized MoS2 into a thin film of three-dimensional (3D)-interconnected carbon nanofibers (CNFs), producing a MoS2/CNFs film. The free-standing MoS2/CNFs thin film can be used as anode for NIBs without additional binders or carbon black. The MoS2/CNFs electrode exhibits a high reversible capacity of 260 mAh·g–1, with an extremely low capacity loss of 0.05 mAh·g–1 per cycle after 2, 600 cycles at a current density of 1 A·g–1. This enhanced sodium storage performance is attributed to the synergistic effect and structural advantages achieved by embedding MoS2 in the 3D-interconnected carbon matrix.