Ireland ended their year on a demoralising note as they were held to a 1-1 friendly draw at home by New Zealand on Tuesday.
Ireland failed to qualify for Euro 2024, after finishing second-bottom in their group with six points from eight matches, with their two wins coming against last-placed Gibraltar. They ended their qualification campaign with a 1-0 defeat away to the Netherlands on Saturday.
"Stephen Kenny’s contract as Manager of the Ireland senior men’s national team will not be renewed following the conclusion of the UEFA EURO 2024 qualification process," the FAI said in a statement.
"The Board agrees that now is the right time for change ahead of the friendly matches in March and June 2024 and the next Nations League campaign starting in September 2024."
Kenny replaced Mick McCarthy (64) in 2020 and signed a new contract to remain in charge until after Euro 2024.
"(He) has given debuts to a significant number of new and younger players and this will serve as a solid platform for whoever now takes this group of players forward."
Kenny said on Tuesday he would have liked to continue in his role despite not qualifying for the European Championship, but expected his contract not to be renewed.
"It would be a dream to carry on and manage the team, but my instinct is that’s not going to happen. The evidence suggests that probably won’t happen, so I respect that as well," he said.
"It's been a privilege in that regard, the greatest honour you can have. Whatever you did in life, it would be a step-down, no matter what you did, but that's the way it is.
"We have had a lot of setbacks and I suppose that's why I'm not getting a new contract if that's the case. International football is ruthless, that's the nature of it. I know that, I understood that, but that's the way it is."
The recruitment process for a new coach is underway, the FAI said.
