O'Neill confirmed that Keane will have be involved in all matters, but dismissed fears that the former Manchester United midfielder will make the final decisions.
"I think Roy has a very big role to play," O'Neill told the Irish Examiner.
"I will listen to him. He's an iconic figure in football, but at the end of the day there will be one voice and that will definitely be me.
"He will be excellent for me, but more importantly he will be excellent for the Republic."
O'Neill also said that being named manager was a big achievement personally, while outlining Ireland's aims under his management.
"I'm very excited. Managing the team is a genuine privilege. We've got one aim and that's to qualify for the European Championships in 2016."
O'Neill will take charge of Ireland for the first time on Friday when they host Latvia.