The Brazilian-born player, who played twice for Stoke’s first team after moving to the club in 2014, was registered with Moldovan side Sheriff Tiraspol at the time of his death.
After joining them in February he made 10 appearances as Sheriff won the Moldovan National Division title.
Teixeira also played for Kosice, Slovan Bratislava, Banik Ruzina and Dukla Banska Bystrica and made eight appearances for Fleetwood Town during a loan spell from Stoke in 2015.
A statement on Stoke’s website read: “Stoke City extends sincere condolences to the family of former defender Dionatan Teixeira following his untimely passing at the age of 25.”
Chief executive Tony Scholes added: “Dionatan was a hugely popular member of our squad and it’s difficult to comprehend that he has passed away at such a young age.
“Our thoughts and prayers go out to his young family and friends at such a difficult time.”