| Works L&W Group S.R.O | Construction | 2012 |
| World Event AS | Administrative & support | 2003 |
| Wpi-Consult AS | Manufacturing | 2016 |
| WPM AS | Wholesale & retail | 2020 |
| WSG Holding AS | Professional & scientific | 2021 |
| Wærholm Invest AS | Real estate | 2013 |
| XBP Invest AS | Financial services | 2018 |
| Xcelis AS | | 2025 |
| Xceptor AS | Professional & scientific | 2005 |
| Xcita Invest AS | Real estate | 2018 |
| Xix AS | Real estate | 2018 |
| XL Eiendom AS | Professional & scientific | 2006 |
| Xo Transport AS | Transport & logistics | 2006 |
| Xy Nordic AS | Wholesale & retail | 2023 |
| Yatiri AS | | 2024 |
| Yay Learning AS | Information & communication | 2023 |
| Yb Service AS | Other services | 2018 |
| Yess AS | Construction | 2022 |
| Yieldr AS | Information & communication | 2022 |
| Yips Holding AS | Wholesale & retail | 2020 |
| Yips Møllekvartalet AS | Hospitality | 2023 |
| Ykos AS | Financial services | 2013 |
| Ylv Holding AS | | 2023 |
| Yoda Invest AS | | 2020 |
| Your Time Frisør Og Velvære AS | Other services | 2019 |
| Ypc Nuf | Construction | 2014 |
| Yuns Mat AS | Hospitality | 2023 |
| Z Holding AS | Real estate | 2005 |
| Zanshin AS | Education | 1998 |
| Zaptec ASA | Wholesale & retail | 2012 |
| Zaptec Charger AS | Wholesale & retail | 2013 |
| Zaptec IP AS | Professional & scientific | 2007 |
| Zaptec Power AS | Wholesale & retail | 2016 |
| Zaui Solutions AS | | 2022 |
| Zayco Invest AS | | 2022 |
| Zebra Consulting Stavanger AS | Information & communication | 2023 |
| Zebra Media Stavanger AS | Professional & scientific | 2018 |
| Zelis AS | Real estate | 2013 |
| Zer Eiendom AS | | 2025 |
| Zeticeta AS | Information & communication | 2024 |
| Zettabeth Kvadrat AS | Wholesale & retail | 2023 |
| ZIGMA360 AS | Information & communication | 2000 |
| Zigzagg Invest AS | | 2025 |
| Zimmermann Økonomi Og Regnskap AS | Professional & scientific | 2016 |
| Zorlu Invest AS | Wholesale & retail | 2020 |
| Ztil Maxi AS | Wholesale & retail | 2013 |
| Zymetech AS | Professional & scientific | 2007 |
| Zypher Solutions AS | Information & communication | 2026 |
| Åb Entrepenør AS | Arts & recreation | 2025 |
| Ådnanes Invest AS | Construction | 2022 |
| Ådne Holding AS | | 2026 |
| Ådnøy Avløp SA | Water & waste | 2020 |
| Ålgård Eiendom AS | Real estate | 2006 |
| Ålgård Handel & Industri AS | | 1968 |
| Ålgård Holding AS | Wholesale & retail | 1982 |
| Ålgård Maskinutleie AS | Manufacturing | 2011 |
| Ålgård Næring AS | Real estate | 2017 |
| Ålgård Thai Mat AS | Hospitality | 2026 |
| Ålgård's Auto AS | Wholesale & retail | 1997 |
| Ålgårdslåtten 12 AS | Real estate | 2024 |
| Ålgårdsnuten AS | Real estate | 2021 |
| Åreskjold Bakke AS | | 2024 |
| Åreskjold Sandtak AS | Mining & quarrying | 2024 |
| Århaugen Consulting AS | Professional & scientific | 2022 |
| Årsvoll AS | Real estate | 2019 |
| Årsvoll Biff Da | Agriculture & fishing | 2016 |
| Årsvollgård AS | Real estate | 2021 |
| Årsvollsveien 19 AS | Real estate | 2000 |
| Årsvollveien 63/87 AS | Real estate | 2013 |
| Årsvollveien Eiendom AS | Real estate | 2022 |
| Årvik AS | Construction | 2019 |
| Ås Maskin AS | Wholesale & retail | 2024 |
| Åsedalen Service AS | Wholesale & retail | 2022 |
| Åsheim Holdings AS | | 2024 |
| Éveillé AS | Wholesale & retail | 2026 |
| Øglænd Hage Og Anlegg AS | Administrative & support | 2015 |
| Øglænd Invest AS | | 2022 |
| Øglænd Næring AS | Real estate | 2018 |
| Øglænd-Norheim AS | Health & social care | 2006 |
| Øglændhuset AS | Real estate | 2005 |
| Øie Invest AS | Financial services | 2005 |
| Øinvest AS | | 1994 |
| Øivind Pedersen AS | Construction | 1984 |
| Økm AS | | 2023 |
| Øksnevad Innovasjon AS | Professional & scientific | 2024 |
| Ølv Holding AS | Professional & scientific | 2015 |
| Ølva SA | Water & waste | 2020 |
| Ønj Holding AS | Professional & scientific | 2010 |
| Øra Invest Eiendom AS | Real estate | 2005 |
| Ørland Holding AS | Real estate | 2017 |
| Ørland Transport AS | Transport & logistics | 1996 |
| Ørnatua 1 AS | Real estate | 2013 |
| Øs Varme AS | Wholesale & retail | 2018 |
| Øs Varme Holding AS | | 2018 |
| Øst Næringspark AS | Real estate | 2009 |
| Øst Næringspark II AS | Real estate | 2010 |
| Østbø Investment AS | Real estate | 1990 |
| Østebrød Eiendom AS | Real estate | 2006 |
| Østebrød Holding AS | Real estate | 2008 |
| Øster Hus AS | Real estate | 2004 |