Rapid urbanization and population growth are stressing the present agricultural systems and could threaten food security in the near future. Sustainable development in agriculture is a way out to such enormously growing food demand. Plant growth-promoting bacteria (PGPB) are considered pivotal to providing adequate nutrition and health to plants and maintaining soil microbial dynamics. In the present study, municipal solid waste composts (MSWC) were studied for the presence of PGPB and their growth-promoting characteristics such as ammonium production, siderophores production, phosphorus solubilization and potassium solubilization, IAA (indole acetic acid), and HCN production. Four promising isolates were chosen and identified through 16S rRNA sequencing as Bacillus sp. strain L5-1, Bacillus pumilus strain EE107-P5, Bacillus sp. strain LSRBMoFPIKRGCFTRI6 and Bacillus sp. strain LPOC3. The potential of isolates is validated using Solanum lycopersicum (tomato) and was found to improve its growth significantly. The findings indicated the presence of potential Bacillus strains in MSWCs, and these composts can be utilized as biofertilizers for urban agricultural practices. However, studies concerning their impact on other crops’ growth and health are still underdeveloped. Since MSWCs might carry hazardous metals or chemicals, their evaluation for the safe application on the crops should also be assessed.