Low-coordinate rare-earth single-ion magnets were successfully constructed via intercalation of lanthanide ions into bulky phenol matrix. Interestingly, the rare-earth complexes crystallized in the same way with the pro-ligand ArOH (Ar = 2,6-Dipp₂C₆H₃, Dipp = 2,6-diisopropylphenyl), allowing for the natural magnetic dilution studies by doping complexes into pro-ligand matrix. Magnetic measurements and theoretical studies demonstrated that both the oblate type dysprosium and prolate type erbium analogs exhibited single-ion magnets (SIMs) behaviors. The bulky phenol ligands provided strong uniaxial ligand field, making the dysprosium SIM possessing blocking barrier up to 961 K.