The Manchester United forward, 19, has not been involved for his country at any level since he was sent home in disgrace from the senior squad in September.
That was after he and fellow Manchester City whizkid Phil Foden broke coronavirus guidelines by inviting two girls back to their hotel room while on international duty in Iceland.
Foden has gone on to regain his place in Gareth Southgate’s team after a fine campaign for table-topping City.
But Greenwood has struggled for form at United, scoring just one Premier League goal this term.
He has four Under-21s caps to his name and will hope to regain some form and confidence while with Aidy Boothroyd’s squad in Slovenia.
Greenwood is joined in the squad by Emile Smith Rowe of Arsenal, PSV’s Noni Madueke and Cheltenham loan goalkeeper Josh Griffiths – all of whom have received their first call-ups.
There is no place for Borussia Dortmund’s Jude Bellingham, though it remains to be seen whether that is due to travel restrictions in Germany or because Southgate wants him in his senior squad.
Due to Covid condensing the club seasons, the group stage of this year’s Euros has been brought forward to the end of March.
England face Switzerland in Koper on March 25, Portugal on March 28 in Llubljana and Croatia back in Koper on March 31.