Magnetic properties of 3d transition metal ion doped methylammonium lead chloride (MAPbCl 3 ) have been studied by ab-initio calculations in the framework of density functional theory. The study of spin-spin interactions reveals that doping (about 2%) of Ti, V, Cr, Mn and Fe at the Pb site of MAPbCl 3 shows stable ferromagnetic ordering along with the half-metallic behaviour. 3d orbital electrons of the dopants are primarily responsible for the origin of the magnetic moment and the remaining part comes from the p-d exchange interaction between the 3d orbital electrons of the dopants and the 6p orbital electrons of Pb in the vicinity of the doping position. Additionally, the band structure calculations suggest that the doped system shows n/p-type semiconducting behaviour. Ferromagnetism, along with semiconducting behaviour in transition metal ion-doped MAPbCl 3, will be suitable for spintronic applications.