Here we collate a database of all known birds, bryophytes, fungi, invertebrates, lichens and mammals that use Sitka spruce (Picea sitchensis) in the UK. Sitka spruce is the most commonly planted commercial tree species in the UK. In total 564 species are listed in the database. For each species we provide a level of association with Sitka spruce, ranging from obligate (only found on Sitka spruce) to cosmopolitan (found on a wide range of other tree species). Data on the ecology of each Sitka spruce associated species were collated: part of tree used, and use made of tree (feeding, roosting, breeding). Data on use or otherwise of 34 other tree species were also collated for each of the 564 species. Full details about this dataset can be found at https://doi.org/10.5285/1ce52c10-e3ab-4996-b9b7-052c70b3c1ba