Nikita Pearl Waligwa, the young Ugandan newcomer who starred in “Queen of Katwe,” the 2016 Disney film about a chess champion’s coming of age, has died of a brain tumor. She was 15.

Her death was announced on Sunday by Gayaza High School, an all-girls boarding school outside the Ugandan capital of Kampala where Ms. Waligwa had been a student.

“You were a darling to many and we have lost you to a brain tumor at such a tender age,” the high school said on Twitter.

The announcement prompted an outpouring of tributes from some of Ms. Waligwa’s co-stars in “Queen of Katwe,” which was based on a 2011 essay in ESPN The Magazine about a chess prodigy in Uganda who grows up in a slum and wins international competitions. The film starred Lupita Nyong’o and David Oyelowo. It was listed as Ms. Waligwa’s only film credit.