N99 or N-99 may refer to:
*
Brandywine Airport, in West Goshen Township, Pennsylvania, United States; formerly assigned FAA LID N99
* , a submarine of the Royal Navy
*
N99 motorway (Netherlands)
*
Nebraska Highway 99
Nebraska Highway 99 is a highway in southeastern Nebraska. It has a southern terminus at the Kansas border south of Burchard and just north of Summerfield, Kansas. Its northern terminus is north of Burchard at an intersection with Nebraska High ...
, in the United States
*
NIOSH N99, a rating for respirators and surgical masks
*
NR-N99 tank droid, a fictional vehicle in the ''Star Wars'' universe
{{Letter-Number Combination Disambiguation