The present study aimed to screen potential plant growth promoting bacterial strain from calcareous soil, and explore it to improve the early cotton seedlings growth through seed bacterization. A bacterial strain NAU-RPJ-35 was found with mineral solubilization of phosphate and potash; production of siderophore, Indole 3-acetic acid (IAA), HCN, cellulase and tolerates 800 mM of salt concentration. The confrontation assay revealed a mycelium inhibition percentage of 93.76% against Sclerotium rolfsii, while 57.39% for Fusarium oxysporum f.sp. lycopersici. Microbial and molecular characters identified the strain as Enterobacter hormaechei. Haemolysis was not observed on blood agar indicates the non-pathogenicity of the strain. Data from TLC, Arnow’s, and Csaky’s assays indicated that the strain produced a catechol type of siderophore. Further, an in vitro study on seed bacterization of American (Gossypium hirsutum G.Cot.10 and G.Cot.44) and Desi (Gossypium herbaceum GN.Cot.25 and GN.Cot.27) cotton seeds with this strain exhibited enhanced morphological traits viz., germination percentage, fresh shoot and root weight, as well as dry shoot and root weight; whereas root to shoot ratio was notably higher in Desi cotton genotypes. Furthermore, the biochemical traits such as chlorophyll content, protein content, and total sugar content were statistically improved in all bio-primed cotton seedlings compared to unprimed seedlings; while proline content, SOD, and POD levels remained unchanged or decreased. The data suggested that Enterobacter hormaechei NAU-RPJ-35 warranting further comprehensive studies to investigate its potential in agricultural management practices.