The game against Oman in Aviva Stadium on Wednesday, August 31 will act as a warm-up to the FIFA 2018 World Cup qualifying campaign, which kicks off for Ireland away to Serbia in Belgrade on Monday, September 5.
These will be the first games for O'Neill's team since UEFA EURO 2016 and they will undergo their first training session on Monday, August 29 in the FAI National Training Centre.
Defender Shane Duffy is suspended for the game against Serbia, while the trio of Seamus Coleman, John O'Shea and Jeff Hendrick will each be assessed by the FAI medical staff once they report into camp on Sunday, August 28.
"After the excitement of UEFA EURO 2016 it seems as if we had little time to enjoy some excellent performances during that tournament," said O'Neill.
"The World Cup qualifying campaign is already upon us and we have a difficult set of fixtures in the coming months.
"The visit of Oman to the Aviva Stadium reminds us of the game they played in Dublin two years ago. That took place immediately before we embarked on our European qualifying campaign.
"This game is ideal preparation for our first qualifier against Serbia in Belgrade a few days later. The Oman game also gives us the chance to play in front of Ireland supporters who enhanced their own reputation in France. We are looking forward to both games."
Republic of Ireland Squad
Goalkeepers: Darren Randolph (West Ham United), Keiren Westwood (Sheffield Wednesday), David Forde (Portsmouth*)
Defenders: Seamus Coleman (Everton), Cyrus Christie, Richard Keogh, Alex Pearce (Derby County) Paul McShane (Reading), John O'Shea (Sunderland), Ciaran Clark (Newcastle United), Marc Wilson (Bournemouth), Stephen Ward (Burnley)
Midfielders: James McClean (West Bromwich Albion), Glenn Whelan (Stoke City), Aiden McGeady, James McCarthy (Everton), Jeff Hendrick (Derby County), Stephen Quinn (Reading), David Meyler (Hull City), Harry Arter, Eunan O'Kane (Bournemouth), Callum O'Dowda (Bristol City), Robbie Brady, Wes Hoolahan (Norwich City)
Forwards: Robbie Keane (LA Galaxy), Shane Long (Southampton), Daryl Murphy (Ipswich Town), Jonathan Walters (Stoke City)
*Indicates player is currently on loan