Zinc phenoxide complexes L¹ZnOAr 1–4 (L¹=Me₂NC₂H₄NC(Me)CHC(Me)O) and L²ZnOAr 5–8 (L²=Me₂NC₃H₆NC(Me)CHC(Me)O) with donor-functionalized β-ketoiminate ligands (L^1/2) and OAr substituents (Ar=Ph 1, 5; 2,6-Me₂-C₆H₃2, 6; 3,5-Me₂-C₆H₃3, 7; 4-Bu-C₆H₄4, 8) with tuneable electronic and steric properties were synthesized and characterized. 1–8 adopt binuclear structures in the solid state except for 5, while they are monomeric in CDCl₃ solution. 1–8 are active catalysts for the ring opening polymerization (ROP) of lactide (LA) in CH₂Cl₂ at ambient temperature and the catalytic activity is controlled by the electronic and steric properties of the OAr substituent, yielding polymers with high average molecular weight (M_n) and moderately controlled molecular weight distribution (MWDs). 1 and 5 showed a living polymerization character and kinetic studies on the ROP of L–LA with 1 and 5 proved first order dependencies on the monomer concentration. Homonuclear decoupled ¹H-NMR analyses of polylactic acid (PLA) formed with rac-LA proved isotactic enrichment of the PLA microstructure.