The group, who had been living on the M50 near Ballymun, had wanted the Irish government to grant them housing and allow them to stay in the country.
However, they departed Dublin Airport just after 1800 BST on Wednesday.
They will be taken to their respective villages in the western part of the country by bus once they arrive.
A Garda spokesperson confirmed that the Roma's decision had followed dialogue with gardai in recent days, and Wednesday's operation had been conducted by officers from Santry and the Garda National Immigration Bureau.
Under Irish law, they were not entitled to work or stay in the country more than three months, but said conditions there were better than at home.
This claim was contested by the Romanian Embassy in Dublin.