Thermoplastic polyurethanes (TPUs) are known for their versatility due to the wide range of macromolecular architectures available. This study focuses on the synthesis and the architecture-properties relationships of new sustainable aromatic TPUs, derived from different potential sustainable resources, such as biomass and plastic waste. Thus, new sustainable aromatic short diols were synthesized from 4–hydroxybenzoic acid and syringic acid, and named HB.diol and Syr.diol, respectively. Subsequently, TPUs were prepared with these original diols as chain extenders, alongside conventional aromatic and aliphatic sustainable chain extenders, like 1,4–benzenedimethanol (BDM) and 1,4-butanediol. The investigation explored the effect of these chain extender structures on the properties of the resulting TPUs, using both aromatic and aliphatic diisocyanates in the synthesis. The thermal and mechanical characteristics of the TPUs were evaluated to identify key structural parameters that influence the properties of the macromolecular architectures. Notably, the presence of aromatic rings enhanced the incompatibility between soft and hard segments (HS), resulting in greater phase segregation. Ether bonds in HB.diol and symmetric structures in BDM enhanced hydrogen bonding, promoting the development of organized and crystalline HS, enhancing phase segregation, thus improving thermo–mechanical and mechanical properties. On opposite, methoxy groups in Syr.diol and the asymmetry of the aromatic diisocyanate hindered the organization of HS, leading to reduced TPUs structuration and lower mechanical properties. Overall, these findings highlight the potential for creating sustainable TPU macromolecular architectures with desirable properties by selecting appropriate raw materials.