It fell from 195th best-ranked university in the world in 2016/17 to 202nd in the QS World University Rankings for 2017/18.
Ulster University was ranked in a band of institutions from 601-650 in 2017/18, similar to last year.
The QS rankings are regarded as one of the most authoritative rankings of universities across the globe.
Just published, they assess around 4,300 institutions and rank almost 1,000.
The ratings are based on a number of factors, including evaluating each university's strengths in research, teaching, academic reputation, staff to student ratio and the number of international staff and students.
The QS World University Rankings show the Massachusetts Institute of Technology (MIT) once again rated as the world's best.
Stanford and Harvard in the USA are ranked second and third in the world respectively.
Cambridge, Oxford, University College London and Imperial College London are all in the top 10, but there has been an overall downward trend for UK universities.
There are 76 UK universities in the international rankings, but the compilers say 51 of them are in a lower place than last year.
Queen's University Belfast (QUB) has fallen out of the top 200 places in the latest global university rankings.