Stoke sign Muniesa from Barca on a free
Muniesa has agreed a four-year contract with the English club who finished 13th last season before appointing Mark Hughes as their manager in May to replace Tony Pulis.
"I'm very excited about moving to England to play for Stoke City and will do everything I can to help the club," the 21-year-old said on his new club's website.
"My season only finished a fortnight ago when the European [Under-21] Championship ended, but I can't wait to get started for Stoke."
Muniesa has been plagued by knee injuries during his short career. He ruptured ligaments in his left knee as a 16-year-old and was out for 10 months, and sustained a similar injury to his right knee in a pre-season game against Hamburg SV last term.
He returned to action for Barca's B team in late February and was part of the Spain squad who won the continental under-21 title last month. He featured just once, coming on as a 79th-minute substitute in a group game against Netherlands.