The Australian National University (ANU) has climbed into the world's top 20 universities, according the latest list of international university rankings.

The latest QS World University Rankings for 2015-16 ranked the ANU as equal 19th in the world with Kings College London.

Last year, the ANU came in at number 25 and was once again ranked the top university in Australia - a position it has held for the past few years.

The rankings are based on a number of measures including academic reputation, employer reputation, research citations and the ratio of staff to students.

ANU vice-chancellor Professor Ian Young said the ranking was "a tremendous outcome for the ANU and its many staff".

QS World University Rankings 2015/16 Ranking University Country 1 Massachusetts Institute of Technology (MIT) US 2 Harvard University US 3 University of Cambridge UK 4 Stanford University US 5 California Institute of Technology US 19= The Australian National University/ Kings College London AUS/UK 42 The University of Melbourne AUS 45 The University of Sydney AUS 46= The University of New South Wales/ The University of Queensland AUS 67 Monash University AUS 98 The University of Western Australia AUS

"It's a remarkable achievement for the university," he said.

"We're the top Australian university to get into the top 20 universities in the world."

Professor Young said there had been a steady improvement in the ANU's rankings.

"Over the last few years we've been investing very strongly in great people across the institution, trying to build the quality of our staff," he said.

"We've also been trying to build an educational experience at ANU which we think rivals anyone in the world.

"We've looked at the basics of what makes a great institution and if you do that it ultimately gets reflected in these sorts of rankings."

The Massachusetts Institute of Technology (MIT) once again took out first place, followed by Harvard in second position and the University of Cambridge in third place.

The ANU came in not far behind Yale University at number 15 - after it dropped from number 10 last year.

The University of Melbourne was the second Australian university on the list at number 42, followed by the University Of Sydney in 45th place.

"The closer you get to the top the more challenging it is," Professor Young said.

"So the challenge for us will be to continue to innovate, to continue to do new things and to continue to build an education which is appealing to our students and sets them up for life."

Globally, the ANU ranked 12th in the world for Arts and Humanities, 18th for Social Sciences and Management and equal 20th for Natural Sciences.

It ranked 26th in the world for academic reputation with an overall score of 99.6 out of 100.