Katy Yeandle, whose three-year-old son Joseph died from neuroblastoma, expressed gratitude to Carr for significantly raising awareness of the rare disease.
Ms Yeandle highlighted that neuroblastoma is not widely known, and Carr's donation has initiated important conversations about childhood cancer.
Carr, a patron of Neuroblastoma UK for nine years, stated it was a privilege to support the charity and use his platform to highlight its vital work.
The charity confirmed the donation will have a "huge impact" on its mission to find better treatments and a cure for neuroblastoma, a rare cancer primarily affecting children under five.