Donald Tusk has won a second term as president of the European Council, with the Taoiseach's backing.
The decision was made despite vociferous opposition from the government in Mr Tusk's native Poland, which had put forward an alternative candidate.
There was speculation that Mr Kenny was being touted for the job, but he denied it ahead of the vote. "I have a job and I'm voting for Donald Tusk this evening," Mr Kenny told reporters. Mr Tusk's re-election was supported by all EU countries bar Poland, and alternative candidates were not considered.
"Grateful for trust & positive assessment by #EUCO. I will do my best to make the EU better," Mr Tusk tweeted after being re-elected for another two-and-a-half year term, starting from June.
Mr Tusk was the only candidate except for Polish MEP Jacek Saryusz-Wolski, whose name was thrown into the mix by the Poland's ruling Law and Justice party at the last minute.
The vote was the only tense moment at the EU summit, where leaders gathered to discuss the economy, migration and the fragile political situation in the Western Balkans.
Brexit was not on the agenda, but the Taoiseach met with British Prime Minister Theresa May on the sidelines of the summit.
He said the UK must pay its bills upon leaving the EU, and expressed concern at the "political challenge" of maintaining an open border in Northern Ireland.
Mr Kenny pleaded for a "sense of realism" in the upcoming Brexit talks, which are due to kick off in April, once the UK officially notifies the EU of its intention to leave.
"The language on both sides here will change in terms of its rhetoric, from time to time, but I think we have to have a sense of realism."