Sub-Officer, or the equivalent in other languages, is a term used in many armed forces used to indicate ranks below commissioned officers. Sub-officer is equivalent to the term warrant officer in the British Commonwealth and the United States. Historically armed forces using the term sub-officer have used it to refer to more senior non-commissioned ranks, typically from sergeant upwards, but the term often covers all ranks that other forces designate non-commissioned. In navies the term is comparable to petty officer.

Sub-Officer, or the equivalent in other languages, is a term used in many armed forces used to indicate ranks below commissioned officers. Sub-officer is equivalent to the term warrant officer in the British Commonwealth and the United States. Historically armed forces using the term sub-officer have used it to refer to more senior non-commissioned ranks, typically from sergeant upwards, but the term often covers all ranks that other forces designate non-commissioned. In navies the term is comparable to petty officer.