The National Foundation for Educational Research, which administered the tests in Northern Ireland, says families and local communities seemed to put a "high value on academic success".
Senior research manager Juliet Sizmur said the international comparison suggested that reading was particularly valued in Northern Ireland.
England was ranked joint eighth, alongside Norway and Taiwan, and England's school standards minister Nick Gibb hailed the positive impact of the phonics system of learning to read.
"Our rise through the global rankings is even more commendable because it has been driven by an increase in the number of low-performing pupils reading well," said Mr Gibb.
This is a much higher ranking than in the international Pisa tests for secondary school pupils, run by the OECD, in which England is not in the top 20 for reading or maths.
Scotland and Wales did not take part in these latest PIRLS tests.
The Republic of Ireland is second only to Russia among European countries.
Comparisons with the last rankings from five years ago depend on which measures are used, says the International Association for the Evaluation of Educational Achievement (IEA), which runs the PIRLS tests with Boston College in the US.
The Netherlands-based IEA says that this year England is 10th, but because "there is no statistical significant difference" with two countries above, they are effectively joint eighth.
Five years ago, the IEA says England was ranked 11th, but as there was no statistical significant difference with US, Denmark, Croatia, Chinese Taipei, and Ireland this "could be interpreted as a joint sixth ranking".
Girls ahead of boys
The IEA's executive director, Dirk Hastedt, says that Russia's success reflects a series of education reforms and a "lot of emphasis on academic excellence" and much more rigour over standards.
Dr Hastedt says such tests reveal international trends in education.
Girls are ahead of boys in almost every country taking the tests, says Dr Hastedt.
He says there are increasing numbers of children in pre-school education - and this seems to be linked to higher performance.
Image copyright Getty Images Image caption Pupils in Russia were the highest achieving in this global test
There are also signs that parents are more likely to get involved in helping their children's learning.
The national comparisons are based on representative samples of pupils, designed by researchers to reflect different regions and types of school.
In England, there were about 5,000 pupils taking the tests last year, drawn from 170 schools. In Russia, the sample was based on about 4,600 pupils in 206 schools.
Most of the pupils taking the tests were aged about 10 - but there were differences depending on the sample.
In Russia and Finland, the average of those taking the tests was 10.8 years, a year older than the average age of those taking the test in Italy and France.
Michael Martin, executive director of the TIMSS and PIRLS International Study Center at Boston College, says that this year's results showed the importance of early years education and parental interest.
"Children whose parents had engaged them in literacy activities - reading books or playing word games - from an early age are better equipped with basic reading skills when they begin primary schools and go on to have higher reading achievements," said Prof Martin.