Pedri, 18, has made 40 appearances, including 26 in La Liga, since joining Barca from Las Palmas last summer.
Spain coach Luis Enrique had monitored the Under-21 player in recent months and has named him in his 24-man squad.
"In the case of Pedri, he has the ideal condition to play in our midfield. He has the quality to do so," Luis Enrique said at a news conference on Monday.
"For some time, we have seen all the possibilities he has to offer. Among the things that I like the most is the calmness and humility he shows on the pitch while being very ambitious. The way he positions himself on the pitch is spectacular. One thing to highlight is the balance that he shows whether it's in attack or defensive play. I'm very eager to see him play with us."
⚠️ OFICIAL | Estos son los jugadores convocados por Luis de la Fuente para disputar la Fase de Grupos del Europeo Sub-21.— Selección Española de Fútbol (@SeFutbol) March 15, 2021
🆚 El combinado nacional, encuadrado dentro Grupo 🅱️, se enfrentará a Italia, Eslovenia y República Checa.
🔗 https://t.co/XxnFuImiMu#U21EURO pic.twitter.com/xXbMiOmGOS
"We have gathered information on his past as this is the first year in the Premier League. He is a young player with a lot of potential," Luis Enrique added. "A very interesting player and we hope he can continue to show his potential.
"I don't have a starting goalkeeper. We have three goalkeepers that can play."
Of the 24 players called up by Luis Enrique, nine of them are 23 and under -- with Pedri being the youngest.
Manchester United goalkeeper David de Gea has kept his place in the squad. Barcelona left-back Jordi Alba, Liverpool midfielder Thiago Alcantara and Leeds United defender Diego Llorente return to the fold after missing previous call-ups.
Spain open their World Cup qualifying campaign against Greece in Granada on March 25 before travelling to Tbilisi to face Georgia three days later. La Roja host Kosovo in Seville on March 31.
Squad in full
Defenders: Pedro Porro (Sporting), Eric Garcia (Manchester City), Sergio Ramos (Real Madrid), Diego Llorente (Leeds United), Inigo Martinez (Athletic Bilbao), Jordi Alba (Barcelona), Jose Luis Gaya (Valencia)
Midfielders: Sergio Busquets (Barcelona), Rodrigo (Man City), Thiago Alcantara (Liverpool), Pedri (Barcelona), Marcos Llorente (Atletico Madrid), Sergio Canales (Real Betis), Koke (Atletico Madrid), Fabian Ruiz (Napoli)