Two-dimensional MoS2 meets porphyrin molecules to form unique 1T′ phase intercalated complexes via a one-step procedure of hydrothermal reactions. The resultant Mn-porphyrin-MoS2 exhibits excellent electrocatalytic activity toward the hydrogen evolution reaction, with a Tafel slope of 35 mV dec−1 and 10 mA cm−2 at an overpotential of 0.125 V. Spin-polarized density functional theory calculations confirmed that the intercalation of Mn-porphyrin into 1T′-MoS2 is quite favourable due to strong charge transfer from Mn metals. Their outstanding catalytic performance could be ascribed to the high electron concentration as well as the low activation barrier of the Heyrovsky reaction.