Summary: The electrode materials with high rate capability are required to meet the ever‐demanding performance of rechargeable batteries. Herein, sulfur‐doped molybdenum phosphide (S:MoP) is prepared using (thio)urea‐phosphate‐assisted strategy and investigated as anode material for Li‐ and Na‐ion batteries. This approach provides the self‐doping of sulfur in MoP lattice that stabilizes the least stable oxidation state of phosphorus (P−3) of MoP through Mo/P–S bonds, enhances the electronic conductivity, and maximizes the Li‐/Na ions adsorption sites. The phase pure hexagonal S:MoP is obtained at 700°C (S:MoP‐7) and the complete reduction of phosphate is confirmed through X‐ray diffraction as well as X‐ray absorption spectroscopy. The presence of chemical bonding of Mo‐P/S and P‐S is detected by X‐ray photoelectron spectroscopy. S:MoP‐7 anode shows excellent rate capability where it delivers 112 mAh g−1 capacity at 12.8 C rate and high stability with 436 mAh g−1 capacity at 100th cycle at 0.1 C rate when tested in lithium‐ion batteries. The S:MoP‐7 as an anode exhibits high rate capability in sodium‐ion batteries and delivers 133 mAh g−1 capacity at 6.4 C rate and 307 mAh g−1 at 0.1 C rate at the 100th cycle. The high performance of the S:MoP‐7 electrode is attributed to the interconnected porous network, increased active sites for Li‐ and Na‐ions via S‐doping, and reduced charge transfer resistance as observed using electrochemical impedance spectroscopy. [ABSTRACT FROM AUTHOR]