Liam Boyce, Billy McKay, Daniel Lafferty, Michael Smith and Ben Reeves have all been cut by Michael O'Neill, the Irish Football Association announced on Saturday.
Grigg, who scored 25 goals as Wigan claimed the League One title this season, opened his international account in Friday's 3-0 friendly victory over Belarus. QPR striker Conor Washington, who scored his second goal in three appearances in that win, has also made the squad.
O'Neill admitted it was a tough to leave out Boyce, who scored 20 times in all competitions for Ross County this season.
"It was very difficult to tell the players who were not going and it was hard choice between Will Grigg and Liam Boyce," he said.
"Liam had a great start to the season in Scotland before suffering a hand injury. Meanwhile, Will just kept on scoring – 28 goals [in all competitions] for his team and helping them to promotion.
"So while it it was difficult decision, I think it was the right one."
Veteran defender Aaron Hughes, who is one short of a century of caps, is also included.
Northern Ireland begin their campaign against Poland in Nice on June 12.
Northern Ireland squad in full:
Defenders: Craig Cathcart (Watford), Jonny Evans (West Bromwich Albion), Gareth McAuley (West Bromwich Albion), Luke McCullough (Doncaster Rovers), Conor McLaughlin (Fleetwood Town), Lee Hodson (MK Dons), Aaron Hughes (Free agent), Patrick McNair (Manchester United), Chris Baird (Derby County)
Midfielders: Steven Davis (Southampton), Oliver Norwood, (Reading), Corry Evans, (Blackburn Rovers), Shane Ferguson (Millwall), Stuart Dallas (Leeds United), Niall McGinn (Aberdeen), Jamie Ward (Nottingham Forest)