The research was carried out by scientists from the Royal College of Surgeons in Ireland, University College Dublin, the University of Edinburgh and the Hebrew University of Jerusalem.
They say it shows the divergence may have began 360 years ago.
It also suggests Travellers are closely connected to Irish settled people.
The researchers found that any genetic disparities between Travellers and settled people in the Republic are largely due to them remaining genetically isolated for several centuries and their numbers decreasing.
It is thought there are about 30,000 people living in the Republic of Ireland who are members of the Travelling community, representing 0.6% of the total population.
Previously it had been thought that Travellers had become displaced between 1845 and 1852 as a result of the Great Famine.
"The findings confirm that the Irish Traveller population has an Irish ancestry and this comes at a time where the ethnicity of Travellers is being considered by the Irish state," the Royal College of Surgeons' Prof Gianpiero Cavalleri said.
"It is important to emphasise that although Irish Travellers show clear features of a genetic isolate, they are genetically very close to settled people in Ireland.
"It is also interesting to observe that the isolation of Travellers from settled people predates the Great Famine.
"However it's important to emphasise that our research estimates the beginning of the social divergence of the Travelling community, rather than their origin."
DNA samples from 42 Irish Travellers were compared with that of 143 European Roma, 2,232 settled Irish, 2,039 British, 5,964 European and 931 individuals from the rest of the world for the study.
Several genetic dating methods were also used to estimate the period when the travelling community began to split genetically from the settled population in Ireland.

The judges said Neurotribes: The Legacy of Autism and How to Think Smarter About People Who Think Differently was a "tour de force" of journalistic and scientific research.
It is the first popular science book to win the prize in its 17-year history.
The shortlist had included Jonathan Bate's Ted Hughes: The Unauthorised Life and Robert Macfarlane's Landmarks.
Historian Anne Applebaum, chair of the judges, praised Silberman's "compassionate journalism" and said he excelled at using stories and anecdotes to explain complex medical issues to a wide audience.
The American author, who is based in San Francisco, has been a science writer for Wired and other magazines such as the New Yorker, the MIT Technology Review, Nature and Salon for more than 20 years.
"We admired Silberman's work because it is powered by a strongly argued set of beliefs: that we should stop drawing sharp lines between what we assume to be 'normal' and 'abnormal', and that we should remember how much the differently-wired human brain has, can and will contribute to our world," Applebaum said.
"He has injected a hopeful note into a conversation that's normally dominated by despair."
Neurotribes, she added, was "a tour de force of archival, journalistic and scientific research, both deeply researched and widely accessible".
In its review of Silberman's book, The Guardian described Neurotribes as "a gripping narrative written with journalistic verve".
The £20,000 Samuel Johnson Prize was won last year by Helen Macdonald's H is for Hawk.
A study of Irish Traveller genetics has suggested that they split socially from the settled population much earlier than thought.
[NEXT_CONCEPT]
Author Steve Silberman has won the £20,000 Samuel Johnson Prize for Non-Fiction for his book about autism.