Nielsen
- Neilsen (disambiguation)
- Neilson (disambiguation)
- Nielsen (crater)
- Nielsen (surname)
- Nielsen Audio
- Nielsen Broadcast Data Systems
- Nielsen Corporation
- Nielsen Fjord
- Nielsen Gallery
- Nielsen Glacier
- Nielsen Holdings
- Nielsen Media Research
- Nielsen Norman Group
- Nielsen Park She-Oak
- Nielsen fixed-point theorem
- Nielsen ratings
- Nielsen–Olesen vortex
- Nielson
- Nilsen
- Nilsson