High pathogenicity avian influenza (HPAI) viruses have rapidly emerged as a major global threat to wildlife, with severe consequences for seabird populations. Albatrosses and petrels (order Procellariiformes) are particularly vulnerable due to their long lifespan, low reproductive rates, and strong site fidelity. Since 2021, HPAI viruses have caused unprecedented mortality in seabird communities worldwide and have expanded into the core range of procellariiform species, including sub-Antarctic and Antarctic regions. In response to the urgent need for timely, species-relevant information, the Agreement on the Conservation of Albatrosses and Petrels (ACAP) established the High Pathogenicity H5Nx Avian Influenza Intersessional Correspondence Group (HPAI-ICG), which developed the ACAP HPAI database—an openly accessible, regularly updated resource that consolidates all known suspected and confirmed HPAI events involving procellariiform birds (albatrosses, petrels, shearwaters, prions, fulmars, and storm-petrels). The database compiles information from global and national reporting systems, scientific literature, genetic repositories, government communications, and direct expert notifications. Events are standardized using transparent case definitions, cross-referenced and validated by subject-matter experts, and complemented by metadata on species, location, diagnostic methods, morbimortality impacts, and availability of genomic data.