The National Center for Education Statistics offers a free school district finder that searches public schools by address. It also operates a separate site that searches private schools. Private companies also offer competing tools online; these finders may be free or ad-supported or charge a fee for information.
If local data is not available online or does not seem to be accurate, calling or visiting the local school district's central office is another way to obtain information about school zones. To find private schools, check a local telephone or business directory. To find religious private schools, contact local churches or religious organizations.