| Aurland Energibygg AS | Aurland | 1995 |
| Auro AS | Solbergelva | 2002 |
| Aurora AS | Finnsnes | 2001 |
| Aurora Eyewear Da | Tomasjord | 2014 |
| Aurora Seaweed AS | Hesseng | 2018 |
| Aurora Spirit Distillery AS | Lyngseidet | 2013 |
| Auroras Gård AS | Ramnes | 2026 |
| Auroras Hjemmebakeri AS | Averøy | 2022 |
| Aurotech Ultrasound AS | Tydal | 2003 |
| Aursfjord Design Ans | Moen | 1988 |
| Aurskog Eiendomsselskap AS | Aurskog | 2016 |
| Aurstad Auto AS | Hovdebygda | 2018 |
| Austad Bredde AS | Kløfta | 2023 |
| Austefjord Mekaniske Verksted AS | Ørsta | 2015 |
| Austevoll Båtservice AS | Bekkjarvik | 2014 |
| Austevoll Elektro AS | Kolbeinsvik | 2013 |
| Austi Norge AS | Larvik | 2004 |
| Austmann Bryggeri AS | Trondheim | 2012 |
| Austrått Kaffebrenneri AS | Voll | 2018 |
| Austvatn Grendeservice AS | Gardvik | 2023 |
| Austvoll Tre & Design AS | Sandnes | 1998 |
| Autagro Møgedal AS | Sand | 2004 |
| Autagro Årdal AS | Årdal I Ryfylke | 1993 |
| Authentic Sweets AS | Lierstranda | 2019 |
| Auto - Tank AS | Dal | 2002 |
| Auto'N AS | Korsvegen | 1988 |
| Auto-Maskin AS | Skjetten | 1980 |
| Autofres AS | Stordal | 2023 |
| Autogen AS | Oslo | 1977 |
| Autoline AS | Borkenes | 1998 |
| Automatek AS | Orre | 2026 |
| Autopåbygg AS | Dal | 2012 |
| Autrenik Ans | Sleneset | 1995 |
| Autronica Fire and Security AS | Trondheim | 1998 |
| Av Anodos AS | Oslo | 2022 |
| Av Maskinservice AS | Øvrebø | 2021 |
| Avant-Garden AS | Bergen | 2002 |
| Avatech Ans | Oslo | 1999 |
| Avax Holding SA | Oslo | 2006 |
| Avdem Gardsysteri AS | Lesja | 2001 |
| Avelenore AS | Oppegård | 2025 |
| Avempro AS | Krokstadelva | 2016 |
| Aven Holding Kragerø AS | Kragerø | 2021 |
| Aven Holmestrand AS | Holmestrand | 1968 |
| Avenas AS | Inderøy | 2023 |
| Aventus Energy Espana Nuf | Es-35008 Las Palmas | 2026 |
| Avermann Betonfertigteiltechnik GmbH & Co. KG | De-49078 Osnabrueck | 2018 |
| Avery Dennison NTP AS | Gaupne | 1988 |
| Averøy Håndbryggeri AS | Averøy | 2019 |
| Averøy Sandblåseservice AS | Averøy | 2011 |
| Averøy Ventilasjonsteknikk AS | Averøy | 1985 |
| Avf AS | Alta | 2025 |
| Aviation Technic Norway AS | Sandefjord | 2024 |
| Avishuset Bryggeri AS | Bryne | 2018 |
| Avitech AS | Drammen | 2019 |
| Avlabs AS | Oslo | 2025 |
| Avlabs Holding AS | Oslo | 2025 |
| Avm Valves AS | Tønsberg | 2006 |
| Avs Pipefit Nuf | Lt-91286 Klaipeda | 2021 |
| Awah BV | Be-2220 Heist-Op-Den-Berg | 2024 |
| Awi Maskin AB Nuf | Se-232 37 Arlöv | 2023 |
| Axel Andersen AS | Drammen | 1996 |
| Axel Andersen Holding AS | Drammen | 2012 |
| Axel Brun Invest AS | Drøbak | 2005 |
| Axess Technologies AS | Molde | 2014 |
| Axicon AS | Lørenskog | 1991 |
| Axis | 500 02 Hradec Kralove | 2009 |
| Axis Audio AS | Melhus | 2022 |
| Axis Communications Norge AS | Asker | 2014 |
| Axitec Anlegg AS | Tveit | 2023 |
| Axnes AS | Grimstad | 1995 |
| Ayis AS | Oslo | 2019 |
| Aym AS | Oslo | 2024 |
| Az Båtservice AS | Nesbru | 2023 |
| Azenta UK Ltd | Manchester M44 5Ay England | 2013 |
| Azf (Ireland) Ltd | Clonmel 6 Tipperary | 2008 |
| Azg Ausbein Und Zerlege Service Sarl | Kristiansand S | 2000 |
| Azienda Vitivinicola Nervi Societa Agricola S.R.L. | It-13046 Gattinara (Vc) | 2015 |
| Asbjørn J. Hansen A/S | Notodden | 1988 |
| Aune Kjøtt A/S | Soknedal | 1988 |
| B & M Holding Dalasjøen AS | Austafjord | 2016 |
| B Innvær AS | Bremnes | 1987 |
| B O Betong Levanger AS | Inderøy | 1992 |
| B Point S.R.O. | Oslo | 2011 |
| B Strand Eiendom AS | Lysøysundet | 2006 |
| B&A Drift Da | Hønefoss | 2025 |
| B&G Rammeverksted AS | Langevåg | 2019 |
| B&U Service AS | Porsgrunn | 2023 |
| B+M Surface Systems GmbH | De-33632 Eiterfeld | 2023 |
| B-O Service AS | Averøy | 1988 |
| B. Culture AS | Oslo | 2020 |
| B. Farnes AS | Holmestrand | 2019 |
| B. Hoan Holding AS | Drammen | 2023 |
| B. Marina AS | Holmestrand | 2025 |
| B.E. Invest AS | Dølemo | 2005 |
| B.R. Service AS | Espeland | 2016 |
| B155 Holding AS | Skatval | 2024 |
| B2B Metallarbeid AS | Drammen | 2013 |
| BAAD1 AS | Grimstad | 2014 |
| Baas Component AS | Lillestrøm | 1986 |