They start their Group C campaign against Poland in Nice at 5pm.
They are currently unbeaten in 12 games.
No country competing at the tournament has a longer undefeated run.
Manager Michael O'Neill says he's been very happy with their build-up to the tournament.
Elsewhere in Group C, World Cup champions Germany start their bid against Ukraine in Lille at 8pm.
Before that, Turkey face Croatia as Group D gets underway in Paris at 2pm.
