ABSTRACT Organic afterglow materials have emerged as promising platforms for long‐lived luminescence, yet their performance is often limited by molecular motion, nonradiative decay, and restricted excitation pathways. Rare‐earth‐mediated confinement offers a powerful means to overcome these challenges by integrating organic emitters with rare‐earth‐doped materials embedded in polymers or engineered nanostructures. These hybrid architectures enhance molecular rigidity, stabilize excited states, and enable finely tuned energy‐transfer processes, while also expanding excitation modes to include X‐rays and electrical bias. Recent developments from single‐particle afterglow enabled by nanoengineered lanthanide transducers to electrically driven afterglow in ligand‐functionalized NPs demonstrate the extensive design space generated through rare‐earth–organic coupling. This review discusses emerging mechanisms, representative system designs, and key principles for rare‐earth‐mediated tuning of organic afterglow under confinement, and highlights future opportunities for developing multifunctional luminescent platforms for imaging, sensing, and optoelectronic applications.