In this work, a total of 72 samples of non-thermally treated commercial table olives were obtained from different markets of the world. Then, prokaryotic diversity in olive biofilms was investigated by metataxonomic analysis. A total of 660 different OTUs were obtained, belonging to Archaea (2.12%) and Bacteria domains (97.88%). From these, 41 OTUs with a proportion of sequences ≥ 0.01% were studied by compositional data analysis. Only two genera were found in all samples, Lactobacillus, which was the predominant bacteria in the biofilm consortium (median 54.99%), and Pediococcus (26.09%). Celerinatantimonas, Leuconostoc, Alkalibacterium, Pseudomonas, Marinilactibacillus, Weissella, and the family Enterobacteriaceae were also present in at least 80% of samples. Regarding foodborne pathogens, only Enterobacteriaceae, Vibrio, and Staphylococcus were detected in at least 91.66%, 75.00%, and 54.10% of samples, respectively, but their median values were always below 0.15%. Compositional data analysis allowed discriminating between lye treated and natural olive samples, as well as between olives packaged in glass, PET and plastic bags. Leuconostoc, Celerinatantimonas, and Alkalibacterium were the bacteria genera with a higher discriminant power among samples. These results expand our knowledge of the bacteria diversity in olive biofilms, providing information about the sanitary and hygienic status of this ready-to-eat fermented vegetable. The world's olive grove consists of more than 10 million hectares, of which over 1 million are destined to table olives, which constitute the most important fermented vegetable in the Mediterranean countries, with also noticeable productions in South America, USA and Australia. The last consolidated worldwide table olive balance shows that its consumption in 2018/2019 season was above 2.7 million tons 1. Among the various processing methods, alkali-treated olives (Spanish style), ripe olives by alkaline oxidation (Californian style) and directly brined olives (natural black or green olives) are the most common 2. Besides, the industry makes diverse commercial presentations (mainly whole, pitted, and sliced) and use different packaging material (glass, PET, or bags, sometimes under vacuum) which lead to a great variety of products. Packaged table olives can be stabilized by pasteurization or sterilization, guaranteeing the absence of viable microbial cells. However, many times, they are preserved by their physic-chemical characteristics (pH, free acidity and salt) with or without use of preservatives. In these cases, the presence of microorganisms is usual 2. Because of the natural antimicrobial compounds of these fruits and the low pH and high salt levels reached during fermentation, table olives have a long history of microbial safety. However, in the absence of correct and hygienic handling practices, diverse microbial hazards may appear such us botulism, mycotoxins, biogenic amines or foodborne pathogens 3. Thus, the study and control of the bacteria biodiversity during table olive...