The optoelectronic, electrocatalytic, and photocatalytic properties of new tin selenides are of great significance for various energy applications. Herein, a facile solvothermal reaction of Sn, Se, and MnCl 2 in 1,3-propodiamine (1,3-dap) solution at 150 °C for 7 days was used to achieve a new type of one-dimensional (1D) organic hybrid manganese−tin selenide [Mn 2 (1,3-dap) 4 (μ-1,3-dap)Sn 2 Se 6 ] n (MnSnSe-1), whose 1D framework is built up from the linkage of rare unsaturated binuclear [Mn 2 (1,3-dap) 4 (μ-1,3dap)] 2+ cations and dimeric [Sn 2 Se 6 ] 4− anions. The combination of MnSnSe-1 and Ni nanoparticle is first applied for the preparation of a Ni/MnSnSe-1/NF electrode (NF = porous Ni foam) as the efficient electrocatalyst for the hydrogen evolution reaction (HER), indicating excellent HER electrocatalytic property with an overpotential of 117 mV at 10 mA•cm −2 in a neutral medium. Owing to its narrow absorption edge of 1.65 eV, implying prominent harvesting ability in the visible-light region, MnSnSe-1 shows a remarkable photocurrent response and excellent visible-light-driven photocatalytic property for the degradation of methylene blue in aqueous solution.