An intelligence officer is a person employed by an organization to collect, compile, or analyze information (known as intelligence) which is of use to that organization. The word "officer" is a working title, not a rank, used in the same way a "police officer" can also be a sergeant, or in the military, in which non-commissioned personnel may serve as intelligence officers. Organizations which employ intelligence officers include armed forces, police, and customs agencies.

Intelligence officers make use of a variety of sources of information, including:

• Communications intelligence (COMINT)
• Human intelligence (HUMINT)
• Imagery intelligence (IMINT)
• Measurement and signature intelligence (MASINT)
• Open-source intelligence (OSINT)
• Signals intelligence (SIGINT)

Titles and responsibilities common among intelligence officers include:

• Field officer: An officer who manages the intelligence collection plan for specific missions in foreign countries.
• Case officer: An officer who runs intelligence agents in order to collect raw intelligence information. Case officers spend their time recruiting and exploiting source agents in order to collect HUMINT.
• Collections officer (collector): An officer that works to prevent detection, penetration, manipulation, and compromise of the intelligence agency, its operations, and overall national security by foreign, domestic, or hostile agents. Often counterintelligence officers are law enforcement officers, as is the case with the Special Agents of the Federal Bureau of Investigations Counterintelligence Division and the Diplomatic Security Services Counterintelligence.

Intelligence officers are essential to operational planning and ultimate success in military operations. They lead and perform intelligence activities across the full range of military operations, oversee the analysis and merging of collected intelligence, develop intelligence plans and policies, produce accurate intelligence analysis, exchange intelligence with other services, agencies, and governments, and integrate intelligence with combat operations. Intelligence officers are experts in a certain topic or subject matter area, and they perform in-depth analysis into foreign militaries, including their defense systems, budgets, and leaders. They also travel to perform field studies related to their area of expertise.