Epoxy resins have been used in structural adhesives, surface coatings, engineering composites and electrical laminates due to their excellent mechanical, thermal and adhesive properties, high chemical resistance, low shrinkage rates during curing, and ease of processing. They have also been widely utilized as the main component of prepregs used in the preparation of composite materials for aviation, automotive, and defense industry applications in recent years. The interest has been increasing on the use of one-component epoxy resins in prepregs over the last decade due to the fact that they can offer advantages in terms of processability, safety, and final product quality. One-component epoxy resins are ready-to-use systems consisting of epoxy resins and curing catalysts. The selection of the curing catalysts for one-component epoxy resins is very important in terms of extension of the shelf-life and control of the curing behavior of formulations. Up to now, catalysts or catalyst systems that can be activated by external stimuli such as thermal irradiation, photoirradiation, ultrasonic irradiation, and electron beam have been used to prevent premature onset of curing and fine-tune the targeted curing temperature for formulations. Thermally latent catalysts or catalyst systems have been more widely utilized in one-component epoxy resins due to their ease of use. Thermally latent catalysts work based on two mechanisms. The first mechanism is based on the principle that the catalyst does not dissolve in epoxy resin due to its crystalline structure and dissolves and becomes active through melting at high temperatures. The second mechanism is based on the principle of using a precursor compound that is not active at room temperature, but is activated by the effect of the external stimulus at high temperatures. The catalyst is present in the precursor compound as either in a complex or conjugate form. In this presentation, a novel polymer-amine based thermally latent catalyst system that works based on the second mechanism will be introduced. The polymer used in the catalyst system has unique and predictable properties. The precise control of the molecular weight, polydispersity, composition, functionality, and topology of the polymer is expected to both improve the shelf-life of one-component epoxy resins and prepregs and control their curing temperatures. The presentation will include a broad discussion of the design, synthesis, and properties of the polymer system followed by examples of the polymer-amine based thermally latent catalysts that will be used in one-component epoxy resins and prepregs used in the preparation of composites.