Peacock-Farrell is part of the group selected for friendlies against Panama and Costa Rica less than two months after making his international debut at Under-21 level.
The 21-year-old was selected by coach Michael O’Neill after finishing the season as first choice at Elland Road.
Peacock-Farrell got his chance under United head coach Paul Heckingbottom following Felix Wiedwald’s loss of form and a neck injury sustained by Andy Lonergan.
His convincing performances have given him a chance of another run next season, though Leeds are planning to sign a new goalkeeper in the transfer window following Wiedwald’s failure to adapt to the Championship after a Â£500,000 move from Werder Bremen.
O’Neill, who was understood to have spoken about taking Peacock-Farrell to the World Cup as third choice had Northern Ireland come through the qualification play-offs in November, said: “Bailey Peacock-Farrell has been a work in process. He’s taken his chance at Leeds. It’s important now to see him in the squad.”
United winger Stuart Dallas has also been included for the meetings with Panama on May 30 and Costa Rica on June 3.
He and Peacock-Farrell were joined in O’Neill’s squad by Gavin Whyte, the Crusaders winger who Leeds are looking to bring to Elland Road this summer.
Whyte has caught the eye with his prolific goalscoring for Crusaders and Leeds are one of a number of English clubs looking to land the 22-year-old.