<p>Luminescent Fe(III) complexes have received increasing attention in recent years. However, upconversion luminescence from Fe(III) complexes has not been explored yet, due to the low photoluminescence quantum yields (PLQYs) of Fe(III) complexes, as well as a significant challenge in combining a proper sensitizer and Fe(III) activator. In this work, a novel ion-paired Fe(III)-Yb(III) complex [Fe(phtmeimb)₂][Yb(ND)₄] was designed and synthesized, where the cation [Fe(phtmeimb)₂]⁺ (phtmeimb = phenyl[tris(3-methylimidazol-1-ylidene)]borate) arming the highest PLQY among Fe(III) complexes so far was employed as activator, and the anion [Yb(ND)₄]^- (ND = 3-cyano-2-methyl-1,5-naphthyridin-4-olate) featuring a large absorption cross-section at 980 nm was constructed as sensitizer. Upon the excitation of 980 nm, red doublet ligand-to-metal charge transfer (²LMCT) emission of [Fe(phtmeimb)₂]⁺ was realized both in solution and doped film through a cooperative sensitization upconversion process. This is the first time to achieve Fe(III) complex-based emission using the near-infrared light excitation, demonstrating the great potential of luminescent Fe(III) complexes as activators in the upconversion luminescence field and promoting the development of fundamental research on the iron-based optical functional materials.</p>