CIO

CIO may refer to:

Governmental organizations

 * Central Imagery Office, an office of the US Department of Defense that was a predecessor of the National Geospatial-Intelligence Agency
 * Central Intelligence Office, the national intelligence agency of the former South Vietnam
 * Central Intelligence Organisation, the national intelligence agency of Zimbabwe
 * Corruption Investigation Office for High-ranking Officials, a government agency of South Korea

Non-governmental organizations

 * Centro de Investigaciones en Optica, a Mexican research centre in optics
 * Charitable incorporated organisation, a form of legal entity for non-profit organizations in the United Kingdom
 * Comité international olympique or International Olympic Committee, an international sports federation
 * Congress of Industrial Organizations or Committee of Industrial Organization, a 1935–1955 national trade union centre that merged into the AFL-CIO
 * Credit and Investments Ombudsman, an Australian dispute resolution service

Titles

 * Chairperson-in-office, an official of a member state holding the presidency of an international organization
 * Commonwealth Chairperson-in-Office, an official of the Commonwealth of Nations
 * Chief information officer, the head of information technology
 * Chief innovation officer, the head of innovation, responsible for innovation management
 * Chief investment officer, the head of investments

Other uses

 * CIO (magazine), both print and online
 * Concurrent input/output, a feature in the JFS file system
 * Conventional International Origin, a conventionally defined reference axis of the pole's average location
 * "Cry it out", an aspect of the Ferber method for solving childhood sleep problems
 * City One station, Hong Kong, MTR station code