Information on forest pest outbreaks, their management and surveillance activity for both Northern Ireland and the Republic of Ireland are documented in a series of forestry annual governmental reports (written by the Northern Ireland Forestry Service, Coillte, The Department of Agriculture, Food and the Marine and the Republic of Ireland Forestry and Wildlife Service). We collated 102 of these annual reports covering the period 1970 - 2020 (51 reports for each of Northern Ireland and the Republic of Ireland). The information on forestry pests available in these reports was digitised via a data extraction protocol and a dataset of the results of this are recorded in the ODonnell_et_al_2024.csv file. The readme file README_ODonnell_et_al_2024.txt is intended to explain the ODonnell_et_al_2024.csv file, and all of the information contained within.