Nio

Nio or NIO may refer to:
 * Nio (Buddhism), guardians of the Buddha
 * Nio Inc., a Chinese electric automobile manufacturer
 * Nicaraguan córdoba, currency by ISO 4217 currency code
 * National Institute of Oceanography (disambiguation), several organizations
 * National Institute of Ophthalmology (disambiguation), several organizations
 * Neurotechnology Industry Organization
 * Non-blocking I/O (usually "NIO"), a collection of Java programming language APIs introduced with the J2SE 1.4 release of Java by Sun Microsystems
 * Northern Ireland Office, an arm of the United Kingdom government, responsible for Northern Ireland affairs
 * Nickel(II) oxide, NiO
 * Liang (surname), pronounced and romanized as Nio in several southern Chinese variants