The ring-opening metathesis polymerization (ROMP) is a powerful methodology to generate synthetic macromolecules whose structures and functions are diverse. Control over the polymer architecture is enabled through the use of well-defined metal alkylidene catalysts, which are able to polymerize a cadre of cyclic olefin monomers in a living manner. Furthermore, specific catalysts possess exquisite chemoselectivity for olefin metathesis in the presence of polar functionality. This functional group tolerance enables ROMP scaffolds to be decorated with various chemical elements that engender the resultant polymers with properties consummate for materials, electronic, and biological applications. Although widely applicable, extant polymers from ROMP, like the majority of synthetic polymers, are non-degradable. They therefore lead to refuse accumulation. A functional and degradable polymer would allow the synthetically useful traits of ROMP to be combined with the growing need for new degradable polymer scaffolds. To address this demand, my thesis identifies bicyclic oxazinones as able substrates for ROMP. The polymerization of bicyclic oxazinones leads to a novel degradable material: polyoxazinones. Through polymerization optimization, polyoxazinones were generated with good control over molecular weight and polydispersity. In addition, synthetic routes were designed to functionalize polyoxazinones to tailor their properties for various applications. Polymers that are both modular and degradable are needed as scaffolds for drug delivery and next-generation vaccine development. To explore the applicability of polyoxazinones for this purpose, the biocompatibility and biodegradability of these ROMP polymers was tested. I show that polyoxazinones are bioinert macromolecules, yet can be functionalized with bioactive ligands to activate immune cells through interactions with specific cell-surface receptors. In addition, I developed an assay based on Förester Resonance Energy Transfer (FRET) to be used to gauge whether polyoxazinoes can degrade inside living cells. Finally, by characterizing the physical properties of polyoxazionones, I found that these polymers possess unusually high thermal stabilities for degradable materials. Therefore, it is envisioned that polyoxazinones can be used to supplement existing non-degradable polymers where high thermal stability is needed. Additionally, I explored methods to generate ROMP-derived copolymers using bicyclic oxazinones and 1,5-cyclooctadiene (COD). Synthetic access to both random and block copolymers was achieved.