Both will be presented on 12 June at a ceremony in London, where the winners of the 2025 Women's Prizes for Fiction and Non-Fiction will also be announced.
Evaristo said she would put the prize money into a project to support other women writers, and will give more details in the autumn.
"I'm not doing it because I'm a multi-millionaire," she joked. "It just feels right to put back in. We should support each other."
The writer said it was "incredibly validating" that her advocacy work had been recognised by the Women's Prize body.
"Women's fiction was in a very bad place when it [the Prize charity] began. Every year it's shone a light... and helped to amplify women's voices."