Fatty acid epoxies serve as valuable starting materials for the development of bio-based polyesters. Here we present a new and efficient catalytic process that allows for the copolymerization of fatty acid-based epoxides and various cyclic anhydrides under attractive process conditions affording functional polyesters. The degree of functionalization and the nature of the polymer backbone can be modulated via monomer design. Postpolymerization cross-linking processes were examined to create rigid macromolecular networks that build on orthogonal polyester functionality, creating possible entries for materials with switchable thermal and mechanical properties.