Whats Kids Are Reading have revealed the reading trends from 1.1 million pupils in over 5,000 schools in both the UK and Republic of Ireland.
Northern Ireland has been crowned the best of the UK regions, followed by Scotland. The lowest scoring country was Wales.
Students in the Republic of Ireland however, ranked higher than any of their peers in UK.
The report shows that students in Ireland are reading more complex books with more comprehension than their northern counterparts
This gap in reading comprehension closes between the two countries when the pupils reach secondary.
The research looked at what primary schools pupils are reading and how they felt about reading.
It found that students who read for their own pleasure scored higher in literacy tests.
The report found that pupils that read daily are three times as likely to read above the expected level compared to those who don't read daily.
A comparison showed students in primary and secondary school are reading more than last year, with the average student reading 240,599 words a year
University of Dundee academic Professor Keith Topping, who analysed the data, said: "Reading for pleasure is a vital component to literacy success, but it is also important to encourage pupils to read more often and to pick books of appropriate reading difficulty for their age."
