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Members of the Candidate phylum Patescibacteria, also called Candidate Phyla Radiation (CPR), are described as ultramicrobacteria with limited metabolic capacities. Wide diversity and relative abundances up to 80% in anaerobic habitats, e.g., in groundwater or sediments are characteristic for <i>Candidatus</i> Patescibacteria. However, only few studies exist for marine surface water. Here, we report the presence of 40 patescibacterial candidate clades at air-sea interfaces, including the upper water layer, floating foams and the sea-surface microlayer (SML), a < 1 mm layer at the boundary between ocean and atmosphere. Particle-associated (>3 µm) and free-living (3–0.2 µm) samples were obtained from the Jade Bay, North Sea, and 16S rRNA (gene) amplicons were analyzed. Although the abundance of <i>Cand.</i> Patescibacteria representatives were relatively low (<1.3%), members of <i>Cand.</i> Kaiserbacteria and <i>Cand.</i> Gracilibacteria were found in all samples. This suggests profound aerotolerant capacities of these phylogenetic lineages at the air-sea interface. The presence of ultramicrobacteria in the >3 µm fraction implies adhesion to bigger aggregates, potentially in anoxic niches, and a symbiotic lifestyle. Due to their small sizes, <i>Cand.</i> Patescibacteria likely become aerosolized to the atmosphere and dispersed to land with possible implications for affecting microbial communities and associated processes in these ecosystems.