Her spokesman, Christine Wolff, said it's nothing to be alarmed about, adding that Crow is doing great and is healthy and happy.
The 50-year-old announced the news about her condition at a recent concert, and then confirmed it in an interview with The Las Vegas Review-Journal. The tumor is a meningioma, and it's typically benign and develops from the protective linings of the brain and spinal cord.
"I worried about my memory so much that I went and got an MRI," she told the The Las Vegas Review-Journal.
Crow, who is currently on tour, battled breast cancer several years ago.
The Associated Press contributed to this report.