The news came on the same day that former Major League infielder Andy Marte died in a separate car crash in the same country.
"Our prayers right now are with Yordano's family as we mourn this young man's passing," Royals general manager Dayton Moore said in a statement.
"He was so young and so talented, full of youthful exuberance and always brought a smile to everyone he interacted with. We will get through this as an organisation, but right now is a time to mourn and celebrate the life of Yordano."
A tweet from Major League Baseball's official account read: "We are devastated by the tragic news that Yordano Ventura, 25, has died in an automobile accident."
Ventura was a member of the Royals team that won the World Series in 2015, when he finished the season with a 13-8 record.
He made his Major League debut in 2013, and finished sixth in the voting for the American League Rookie of the Year award in 2014 after compiling a 14-10 record with a 3.20 ERA.
He pitched in two World Series', in 2014 and 2015, helping the Royals to their second championship title in 2015.
The right-hander had a career ERA of 3.89 and a 38-31 record.
It had earlier been announced that Marte, who played parts of seven seasons with the Cleveland Indians, Atlanta Braves and Arizona Diamondbacks, was killed in a separate incident.
"Words can't express the emotions from the loss of our client Andy Marte. Gone too soon. A great person on and off the field," Marte's agency, JMG baseball, said on Twitter.
"Sad to learn of Andy Marte's death this morning. He was a genuine person who always greeted you with a warm smile. RIP," the Indians tweeted.
Marte broke into the major leagues with the Braves in 2005 before being traded to Cleveland, where he spent five seasons. He returned to major league action in 2014 but played in only six games for Arizona before signing with the KT Wiz in South Korea.
