<p>Plant-associated microbiomes constitute sustainable and ecosystem-based approaches to enhance agricultural performance while reducing the environmental footprint of intensive farming systems, particularly in Mediterranean and semi-arid regions. Such biologically based strategies are increasingly relevant for contributing to global Sustainable Development Goals (SDGs), including food security (SDG 2) and supporting more resource-efficient agricultural practices (SDG 12). In this study, we report for the first time the isolation and comprehensive characterization of a novel epiphytic bacterium from wheat seeds. A new strain, designated STN24, was recovered from wheat (<i>Triticum aestivum</i> L.) seeds sourced from Tunisia. Its identification and functional properties were investigated using polyphasic taxonomic methods and genomic analyses. Strain STN24 is a Gram-negative bacterium exhibiting facultative aerobic growth, lacking spore formation, possessing a rod-shaped morphology, and capable of motility via peritrichous flagella. Whole-genome sequencing (4.67&#xa0;Mb, 55.89% GC content) positioned STN24 within the genus <i>Erwinia</i>, showing close relationships with <i>Erwinia tasmaniensis</i> and <i>Erwinia billingiae</i>. Genomic similarity assessments, including pairwise Average Nucleotide Identity (ANI) and DNA–DNA hybridization, indicate that <i>Erwinia</i> sp. STN24 represents a potentially undescribed species within the genus <i>Erwinia</i>, associated with wheat seeds. Functional characterization revealed that STN24 synthesizes siderophores, produces indole-3-acetic acid (IAA) and exopolysaccharides, exhibits resilience to salinity (5% NaCl), grows over a broad pH range (5–9), and solubilizes zinc, underscoring its potential to improve nutrient accessibility and support plant growth under challenging environmental conditions. Notably, this study combines genomic, physiological, and plant-assay evidence to demonstrate the multifunctional plant growth–promoting potential of this newly identified species. Genomic insights highlighted the presence of genes involved in plant development enhancement and protective effects against plant pathogens, indicating a potential role in reducing reliance on synthetic fertilizers and agrochemicals, in line with environmentally responsible production systems (SDG 12). Importantly, STN24 exhibited no phytopathogenic traits, and seed inoculation significantly improved wheat germination, seedling vigor, biomass accumulation, endogenous auxin levels, and spike development compared to non-inoculated controls, suggesting its contribution to improved crop performance (SDG 2). By promoting crop performance while minimizing chemical inputs, the application of <i>Erwinia</i> sp. STN24 may support the development of more sustainable agricultural systems. Overall, the results of this study highlight the promise of native epiphytic bacteria as environmentally integrative agents for promoting sustainable wheat cultivation in Mediterranean agroecosystems.</p>