The novel, Rowling's first primarily aimed at adults, is set in a fictional English town and deals with the unexplained death of a village resident. The publisher says it's a big novel about a small town.
The cover released Tuesday is mostly red with a yellow border, and shows what looks like an "X" marking a box. The book is 512 pages long. An audio version will also be released.
Rowling's series about Potter, the boy wizard, made her one of the most successful authors in the world.
The Associated Press contributed to this report.