<p>Using density-functional theory calculations, we present a comprehensive investigation of the structural and magneto-electronic properties of CoPt dimers adsorbed on nitrogen-doped divacancies (NDVs) in graphene under applied electric fields. Our study focuses on the microscopic mechanisms governing structural stability, electronic hybridization, and magnetic anisotropy, emphasizing how the combined effects of NDVs and electric fields tune the magnetic response of the CoPt/graphene hybrid system. Our results reveal that NDVs, together with external electric fields, create a chemically active defect landscape that strongly modulates dimer adsorption and bonding behavior. This interplay enhances charge transfer and orbital polarization, resulting in pronounced variations of the magnetic anisotropy energy (MAE). The CoPt dimer exhibits a nearly fourfold increase in binding stability compared to adsorption on pristine graphene, facilitated by partial embedding within the NDV site. Moreover, beyond the intrinsic Co–Pt dipole, four additional local dipoles emerge between Co and the neighboring nitrogen atoms due to charge transfer from Co to N, significantly modifying the effective permanent dipole moment of the composite system. The total magnetic anisotropy originates from two distinct yet coupled contributions: (i) the magnetocrystalline term, <InlineEquation ID="IEq1"> <EquationSource Format="TEX">\(\mathrm {MAE_{SOC}}\)</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi mathvariant="normal">MAE</mi> <mi mathvariant="normal">SOC</mi> </msub> </math></EquationSource> </InlineEquation>, primarily associated with spin–orbit coupling (SOC) on the Pt atom, and (ii) the structural term, <InlineEquation ID="IEq2"> <EquationSource Format="TEX">\(\mathrm {MAE_{str}}\)</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi mathvariant="normal">MAE</mi> <mi mathvariant="normal">str</mi> </msub> </math></EquationSource> </InlineEquation>, induced by electric-field-driven lattice distortions. Their interplay determines the overall effective anisotropy and the direction of the easy magnetization axis. A microscopic analysis of the magnetocrystalline anisotropy, based on the local density of states (LDOS) of the CoPt dimer, demonstrates that <InlineEquation ID="IEq3"> <EquationSource Format="TEX">\(\mathrm {MAE_{str}}\)</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi mathvariant="normal">MAE</mi> <mi mathvariant="normal">str</mi> </msub> </math></EquationSource> </InlineEquation> correlates with orbital anisotropy in agreement with Bruno’s relation. The preferred magnetization direction is further rationalized through the symmetry of the <i>d</i>-orbitals near the Fermi level and their dominant couplings mediated by the orbital angular momentum operators <InlineEquation ID="IEq4"> <EquationSource Format="TEX">\(\hat{L}\)</EquationSource> <EquationSource Format="MATHML"><math> <mover accent="true"> <mi>L</mi> <mo stretchy="false">^</mo> </mover> </math></EquationSource> </InlineEquation>.</p>