Unlike the conventional electronics, spin-based electronics (spintronics) uses electron spin as the information carriers. Therefore, it is required pure spin current for a high spintronic performance that can be generated employing materials with specific electromagnetic structures. In this work, the structural, electronic, and magnetic properties of SnC monolayer doped with 3d transition metals (TMs) are investigated by means of first-principles calculations. Results indicate that SnC monolayer is intrinsically non-magnetic two-dimensional material. Except Ti impurity, the substitutional incorporation of 3d TMs leads to the emergence of feature-rich electronic structures including magnetic semiconductor (in Sc-, V-, and Ni-doped systems) and half-metallic (in Cr-, Mn-, Fe-, Co-, Cu-, and Zn-doped systems) natures, which can be used to generate spin current by means of the spin filtering and spin injection approaches, respectively. Significant magnetism is also induced that is reflected in integer total magnetic moments between 1 and 4mu_B. Herein, magnetic properties are produced mainly by host C atoms in the cases of Sc- and Zn-doped, meanwhile 3d TMs originate mainly the magnetism in the remaining cases with slight contribution from their first neighbor. Further, the magnetic anisotropy is also studied to determine the magnetization direction, while the existence of ferromagnetic (FM) and antiferromagnetic (AFM) ordering in ground state is also analyzed. Results may suggest the TMs-doped SnC monolayer as potential candidates for spintronic applications.