West Indies yesterday confirmed that Phil Simmons has accepted a three-year contract to take over as Head Coach.
His first task will be to lead the team into the three-Test series against England, which starts in just 23 days' time.
Simmons, who had been Ireland coach for exactly eight years, said his goodbyes to the players in the dressing room in Adelaide on Sunday after what proved to be Ireland's final World Cup game against Pakistan.
Afterwards, Simmons admitted he was in talks with the West Indies board.
As expected those reached an amicable conclusion and Cricket Ireland have confirmed their search for Simmons' successor will start immediately.
The third last of Simmons' 116 wins as Ireland coach, in 224 games, was against West Indies and in his farewell comments he admitted his home team were going through a difficult period.
"It was a very difficult decision to leave, but I couldn't turn down the opportunity to coach my home team," he said. "They're going through a difficult period at the moment, but I'm confident I can help to improve their fortunes. I'll always be eternally grateful for the opportunity given to me by Cricket Ireland and in particular CEO Warren Deutrom, and it's been a great partnership over the past eight years.
"I've made some wonderful friends in that time, which has been among the happiest periods in my life."
Simmons added: "The wins in the World Cups over Full Members were all special as we showed the world just what Irish cricket is capable of." Deutrom responded by saying: "Over the last eight years, Phil has overseen our qualification for every major ICC event, identifying our best young talent and producing a series of results that means every team in the world takes us seriously.
"Now our goal is simple, it is to find a replacement for Phil who will take us to our stated vision of playing Test cricket by 2019."
West Indies chief executive Michael Muirhead, in his statement, said: "We welcome Phil back home. He is the right individual for our team at this time and the right fit to usher them into a new era of success."
Australia will face India in the World Cup semi-finals after a comfortable six-wicket win over Pakistan at Adelaide.
Pakistan were dismissed for 213 but they had a chance with Australia at 59 for three after Michael Clarke was dismissed.
But Steve Smith (65) and Shane Watson (64 not out) helped see Australia home with 16.1 overs to spare.