PIRLS (Progress in International Reading Literacy Study) is a project of the International Association for the Evaluation of Educational Achievement (IEA). It is designed to assess the reading achievement of Fourth Class pupils. It was first conducted in 2001, while Ireland took part for the first time in 2011. The 2016 study included an optional component assessing online reading skills, called ePIRLS. The present volume is published at the same time as the IEA’s main reports on PIRLS (Mullis, Martin, Foy, & Hooper, 2017a) and ePIRLS (Mullis, Martin, Foy, & Hooper, 2017b). It summarises the main achievement-related findings from both studies, focussing on Irish performance and findings most likely to be of interest to an Irish audience. A more in-depth series of reports on PIRLS and ePIRLS from an Irish perspective will be released in 2018