Last month, she had begun to walk more slowly, zoo officials said, and seemed to have trouble with her balance.
She appeared to be suffering from spondylosis, a degenerative spinal disorder, which afflicts big cats as they age.
Despite treatment, it became apparent that her health and quality of life were declining steadily, the zoo said.
But for years, she had been on view, an orange, black and white symbol of predatory power, able to give a ferocious roar.
She weighed almost 200 pounds, pounced on unsuspecting ducks and offered a glimpse of a jungle world.
“Soyono is not a tame tiger,” zoo staff members who worked with her wrote earlier in an online posting.
“She was always quick to understand what we wanted,” they reported.
“Sometimes she would work with us to determine exactly what it was that we wanted so she could refuse to do it again. There is a reason that an adult female cat is called a queen. And she has always been regal.”
Soyono was born at the zoo on June 14, 1993, and she gave birth to seven cubs in three litters. They were sent on to other zoos to help keep the endangered species alive. Her mate died in 2010.
The zoo said there are only about 700 of her sisters and brothers in the world, and only 400 of them are in the Indonesian forests from which they come.
Two Sumatran tigers still prowl the zoo’s Great Cats exhibit: a male, Kavi, and a young female, Damai.