Editing O2 (section)

==Vehicles and military==
* [[Cessna O-2 Skymaster]], a military twin-engine light aircraft
* [[Douglas O-2]], a military single-engine observation biplane
* [[O 2-class submarine|''O 2''-class submarine]], a class of submarines of the Royal Netherlands Navy
* [[Oldershaw O-2]], a glider
* [[SP&S Class O-2]], a 1910 steam locomotives class
* [[USS O-2 (SS-63)|USS ''O-2'' (SS-63)]], a 1918 United States O class submarine
* [[GNR Class O2]], a class of British steam locomotives classified O2 by both the GNR and the LNER

===Pay grade===
* O-2, a [[uniformed services pay grades of the United States|uniformed services pay grade of the United States]]:
** [[First lieutenant (United States)]] in the Army, Marine Corps, Air Force, and Space Force
** [[Lieutenant (junior grade)]] in the Navy, Coast Guard, Public Health Service Commissioned Corps, and NOAA Commissioned Officer Corps