Knudsen
- 20th century
- Aase Schibsted Knudsen
- Anthony Carl Knudsen
- Chilton R. Knudsen
- Eugene Peter Knudsen
- Gitte Moos Knudsen
- Gunnar Knudsen
- Jens Martin Knudsen (disambiguation)
- Jesper Knudsen (badminton)
- Karen E. Knudsen
- Keith Knudsen
- Kerry Knudsen
- Knud Knudsen (linguist)
- Knudsen gas
- Knudsen layer
- Knudsen number
- Knut
- Knut Knudsen
- Knutsen
- Konrad Knudsen
- Lactalis
- Lars Knudsen
- Lina Almind Knudsen
- Lisbeth Knudsen
- Martin Knudsen
- Matt Knudsen
- Morrison–Knudsen
- Morten Knudsen
- Per Holm Knudsen
- R.W. Knudsen Family
- Semon "Bunkie" Knudsen
- Sidse Babett Knudsen
- The Doobie Brothers
- Tord Øverland Knudsen
- Valdemar Knudsen
- Vern Oliver Knudsen
- William S. Knudsen