Bacillus species are effective biocontrol agents against tomato diseases. This review discusses the antagonistic mechanisms and biocontrol potential of Bacillus spp. against tomato diseases caused by various pathogens. The main mechanisms of Bacillus spp. include the production of antimicrobial compounds (antibiotics, extracellular enzymes, siderophores, and volatile compounds), competition for nutrients and space, and induced systemic resistance (ISR). Although Bacillus-based plant protection products (PPPs) have been developed and commercialized worldwide for various crops and pathogens, their efficiency is still subject to debate. A combined strategy for controlling tomato diseases based on Bacillus spp. and other available methods (conventional or natural-based) is a promising research field. Bacillus spp. are widely used as biocontrol agents due to their antimicrobial and plant growth-promoting effects. They demonstrate great antimicrobial activity against numerous pathogens and stimulate plant growth and yield. Several Bacillus spp. have been proven to be promising biocontrol agents for controlling tomato pathogens, both in laboratory and field conditions. The review summarizes the most important tomato diseases and pathogens, Bacillus spp. used as antagonists in tomatoes and their mechanisms of action, and combined management strategies involving Bacillus spp. against tomato disease-causing agents. Bacillus spp. have broad application in agriculture due to their ability to produce bioactive compounds, stimulate plant growth, and protect plants from pathogens. They can be used in combination with other methods, such as organic or chemical amendments, to improve biocontrol efficacy. Integrated multi-omics and bioinformatics technologies should be used to understand the mechanisms and efficiency issues of Bacillus spp. agents for managing plant diseases in sustainable agricultural production. The review highlights the importance of Bacillus spp. in the management of tomato diseases and their potential as a sustainable alternative to chemical control.Bacillus species are effective biocontrol agents against tomato diseases. This review discusses the antagonistic mechanisms and biocontrol potential of Bacillus spp. against tomato diseases caused by various pathogens. The main mechanisms of Bacillus spp. include the production of antimicrobial compounds (antibiotics, extracellular enzymes, siderophores, and volatile compounds), competition for nutrients and space, and induced systemic resistance (ISR). Although Bacillus-based plant protection products (PPPs) have been developed and commercialized worldwide for various crops and pathogens, their efficiency is still subject to debate. A combined strategy for controlling tomato diseases based on Bacillus spp. and other available methods (conventional or natural-based) is a promising research field. Bacillus spp. are widely used as biocontrol agents due to their antimicrobial and plant growth-promoting effects. They demonstrate great antimicrobial activity against numerous pathogens and stimulate plant growth and yield. Several Bacillus spp. have been proven to be promising biocontrol agents for controlling tomato pathogens, both in laboratory and field conditions. The review summarizes the most important tomato diseases and pathogens, Bacillus spp. used as antagonists in tomatoes and their mechanisms of action, and combined management strategies involving Bacillus spp. against tomato disease-causing agents. Bacillus spp. have broad application in agriculture due to their ability to produce bioactive compounds, stimulate plant growth, and protect plants from pathogens. They can be used in combination with other methods, such as organic or chemical amendments, to improve biocontrol efficacy. Integrated multi-omics and bioinformatics technologies should be used to understand the mechanisms and efficiency issues of Bacillus spp. agents for managing plant diseases in sustainable agricultural production. The review highlights the importance of Bacillus spp. in the management of tomato diseases and their potential as a sustainable alternative to chemical control.