The former Manchester United midfielder, never one to shy away from controversy, will work alongside new boss Martin O'Neill.
One of the more memorable instances happened before the 2002 World Cup in Japan and South Korea, when Keane was sent home after criticising then-manager Mick McCarthy.
"I am not here to try to change anyone's opinions about me or decisions I have made," Keane told Sky Sports News. "I spent years trying to please everybody and, trust me, it's a waste of time and energy. You just have to do what you think is right.
"I like to set high standards - a lot of people seem to have an issue with that. The criticism I have faced over the last 15 or 20 years has been about me being very demanding and not settling for second best.
"I am certainly not going to apologise for that."
O'Neill's first game in charge of the Green Army will be a friendly match against Latvia on Friday.