An extra 170 million euro (£142m) was raised through visitors attracted by the Gathering.
The homecoming festival contributed a quarter of a million tourists during a "bumper" year for Ireland, according to the Government.
Tourism minister Leo Varadkar said: "The Gathering has been a fantastic experience and a great success. It's delivered the results we were looking for, giving a vital boost to tourism and employment.
"It helped to restore Ireland's status as a premier tourism destination and it strengthened links with the diaspora."
Some markets like the US have seen double digit growth.
As part of the Gathering, a series of events was held to attract those with links to the country back from abroad.