SQN or Sqn may refer to:
*
sine qua non
A ''sine qua non'' (, ) or ''condicio sine qua non'' (plural: ''condiciones sine quibus non'') is an indispensable and essential action, condition, or ingredient. It was originally a Latin legal term for " conditionwithout which it could not b ...
, a Latin legal term
*
Sine Qua Non (wine), a California winery
*
Squadron (disambiguation)
Squadron(s) may refer to:
Military
* Squadron (army), a military unit of cavalry, tanks, or equivalent subdivided into troops or tank companies
* Squadron (aviation), a military unit that consists of three or four flights with a total of 12 to 24 ...
, for which Sqn is a common abbreviation
{{Disambiguation