A series of 2-1-(2,6-dibenzhydryl-4-chlorophenylimino)ethyl-6-1-(arylimino)ethylpyridine ligands (L1–L5) as well as the ligand 2,6-bis1-(2,6-dibenzhydryl-4-chloro-phenylimino)ethylpyridine (L6) were synthesized and reacted with FeCl2·4H2O to afford the iron(II) dichloride complexes LFeCl2 (Fe1–Fe6). All new compounds were fully characterized by elemental and spectroscopic analysis, and the molecular structures of the complexes Fe1, Fe2 and Fe4 were determined by single-crystal X-ray diffraction, which revealed a pseudo-square-pyramidal geometry at iron. Upon activation with either MAO or MMAO, all iron pre-catalysts exhibited very high activity in ethylene polymerization with good thermal stability. To the best of our knowledge, the current system showed the highest activity amongst iron bis(imino)pyridine pre-catalysts reported to-date. The polymerization parameters were explored to determine the optimum conditions for catalytic activity, which were typically found to be 2500 eq. Al to Fe at 60 °C in the presence of MMAO, and 80 °C in the presence of MAO. The resultant polyethylene possessed a narrow molecular polydispersity index (PDI) consistent with the formation of single-site active species. Display omitted