A high-resolution palynological study of a recently acquired core from the southern part of the Ormen Lange field (Norway) over the Danian-aged reservoir interval revealed rich, diverse and well-preserved palynomorph assemblages. Review of these assemblages has allowed the opportunity to formally describe some dinoflagellate cysts previously left in open nomenclature and others recognised for the first time in this well. We propose in this paper the formal description of 10 new species: Achomosphaera eggadania sp. nov., Achomosphaera progranulata sp. nov., Areoligera constricta sp. nov., Areoligera pauciornata sp. nov., Deflandrea variabilis sp. nov., Eurydinium ovatum sp. nov., Glaphyrocysta pseudoreticulata sp. nov., Hystrichosphaeridium pachydermum sp. nov., Operculodinium runtata sp. nov. and Phthanoperidinium ormenlangei sp. nov. All the key diagnostic and morphological features of each species are discussed and compared with those of other forms outside and within the same genera. The new species presented all range throughout the Danian (Early Paleocene) and can be used in conjunction with other previously published markers to support and enhance the stratigraphic breakdown and subdivision of the reservoir interval across the Ormen Lange field, and potentially other areas in the North Sea basin.