Google is to create 500 new jobs in Dublin - taking the workforce at its European headquarters to 1,300 people.
Google opened its European headquarters in Dublin in 2004
The operation deals with customers and advertisers - with the existing 800 staff speaking 45 languages and coming from more than 40 different countries.
Google said the Dublin centre "delivered huge value" to its customers around the world.
The Irish government said the news confirmed the country's status as a European hub for technology firms.
"The announcement further endorses Ireland's ability to provide the technical infrastructure and skills base to support such operations," said the Republic's Minister For Enterprise, Trade and Employment, Micheal Martin.
"Its investment here in Dublin is a huge vote of confidence in our knowledge economy and in our young, educated workforce," he added.
Google, founded in 1998, first located in Ireland in 2003, and opened its European headquarters in Dublin in October 2004.