| Acronym | Definition |
|---|
| NN | Night, Night |
| NN | Non-Nude |
| NN | Nearest Neighbor (algorithm) |
| NN | Noon |
| NN | Neural Network |
| NN | Naked News (show) |
| NN | No No |
| NN | Not Necessary |
| NN | Nizhny Novgorod (Russian football) |
| NN | Not Now |
| NN | No Name |
| NN | Northampton (postcode, United Kingdom) |
| NN | Netscape Navigator |
| NN | NomNom |
| NN | Nationale Nederlanden |
| NN | No Nonsense |
| NN | Newport News Shipbuilding and Drydock Company (US Navy) |
| NN | Network Node |
| NN | Normalnull (German: Sea Level) |
| NN | Nacht und Nebel (German: Night and Fog; WWII prisoners held incommunicado) |
| NN | Nomen Nescio (Latin: I Don't Know the Name) |
| NN | Network Neighborhood (Microsoft Windows 9x) |
| NN | Nonnuclear |
| NN | Not Negotiable |
| NN | Nigerian Navy |
| NN | Nouvelles Normes (classification hôtelière; France) |
| NN | Not Notable (Wikimedia Foundation editing policy) |
| NN | Newport News, VA, USA |
| NN | Not Nominated |
| NN | Normal to Normal |
| NN | Nordic Needle, Inc. (needlework website) |
| NN | Nomen Nominandum (Latin: Name Hitherto Unknown) |
| NN | Non-Participating National (FCC) |
| NN | Nice Nil (spades gaming) |
| NN | Narcolepsy Network, Inc. |
| NN | Negative Notification |
| NN | No Noobs (gaming) |
| NN | Netnexus |
| NN | Nice Nade (gaming) |
| NN | Nevernet (IRC network) |
| NN | Navajo Neurohepatopathy |
| NN | Non Nominatus/Nominata (Latin: Not Named, epigraphy) |
| NN | Nebulous Nonsense |