The Slovenian guard, a four-time NBA All-Star with the Dallas Mavericks, will also pay for grief counselling for classmates and staff as a result of the Serbian tragedy, a spokesman for his charity foundation told ESPN.
Much of Doncic's family is from the Belgrade region. Nikola Jokic (28), the two-time NBA Most Valuable Player who stars for the Denver Nuggets, also pledged his support as he spoke to reporters in Phoenix, where the Nuggets will play the Suns in the NBA play-offs on Friday.
"I am heartbroken by the tragic school shooting in Serbia and the loss of lives, including those of innocent children," Doncic said in a statement posted on social media.
"My thoughts are with the families and the entire community affected by this tragedy."
Doncic reached out to help in the wake of Wednesday's mass shooting and wants to be part of solving long-term needs arising from the incident as well.
"I support and stand with you all during this difficult time," Doncic posted. "Through @LD77Foundation I am exploring both immediate and long-term ways to support the students, faculty, and families affected by the shooting at the Vladislav Ribnikar Elementary School.
"I am committed and I will continue to share updates and ways to support as details become available. #StandWithBelgrade."
Jokic said it was important to find out what those impacted by the shooting need.
"We need to take care of everybody," he said.
Jokic, who is from Sombor, less than 125 miles (200 kilometres) from Belgrade, said he found it hard to imagine such a shooting happening in his native country.
"It's something that I don’t remember it happening in Serbia and I'm really sorry about everything that the families are going through," Jokic said.
"To be honest, I was so surprised. I'm not saying we don't have that, but maybe that's the mindset. But that's not true."
Both players spoke of and posted about their grief over the school shooting before Serbian state-run media reported that eight people were killed and 13 injured late Thursday in another shooting near the town of Mladenovac, about 37 miles (60 kilometres) south of Belgrade.
There an attacker opened fire with an automatic weapon from a moving vehicle and fled, RTS television reported.
