| Kopi Og Print AS | | 2020 |
| Korslund AS | Professional & scientific | 2020 |
| Koru Catering AS | Hospitality | 2023 |
| Koselig Cafe AS | Hospitality | 2025 |
| Koteras Elektrocom AS | Construction | 2019 |
| Kraftverk Øyvind Gundersen AS | Professional & scientific | 2009 |
| Kris Agder Bygg AS | Construction | 2022 |
| Kristoffer Norli Svarva AS | Wholesale & retail | 2006 |
| Kronan AS | Financial services | 2018 |
| Krydra AS | Wholesale & retail | 2020 |
| Kræts AS | Professional & scientific | 2018 |
| Krøgenes Dyrehandel AS | Wholesale & retail | 2019 |
| Krøgenes Næringsutvikling AS | Real estate | 2011 |
| Krøgenes Syd AS | Real estate | 2006 |
| Krøgenes Vekst AS | Real estate | 1990 |
| Krøgeneslåven Ans | Real estate | 2022 |
| Krøgeneslåven AS | Hospitality | 2022 |
| Krøgenesåsen Utvikling AS | Real estate | 2022 |
| Kube Birøkt AS | Agriculture & fishing | 2000 |
| Kulturfabrikken Barbu Scene AS | Arts & recreation | 2024 |
| Kulturhuset Eiendom Arendal AS | Real estate | 2010 |
| Kutts Hairstylist AS | Other services | 2024 |
| Kvalitetshuset AS | Information & communication | 2023 |
| Kvist & Co AS | Wholesale & retail | 2021 |
| Kvåva Holding AS | Real estate | 2021 |
| KW Sørensen Eiendom AS | Real estate | 1990 |
| Kystfiske Sør AS | Agriculture & fishing | 2026 |
| Kystveien Legesenter AS | Health & social care | 2025 |
| Kystveien Legesenter Da | Health & social care | 2013 |
| Kystveien Pizza AS | Hospitality | 2011 |
| Kystveien Service Dekksenter AS | Wholesale & retail | 1990 |
| Kystveien Utvikling AS | Real estate | 2012 |
| Kåre Christensen AS | Construction | 2009 |
| Kåre Eriksen AS | Construction | 1998 |
| L.Samslått AS | Real estate | 2022 |
| Laflamma Arendal AS | Hospitality | 2026 |
| Lagerseksjon AS | | 2026 |
| Lagerutleie AS | Real estate | 2014 |
| Lai Lai Take Away AS | Hospitality | 2014 |
| Landbrukets Hus Arendal SA | Real estate | 1999 |
| Landbø Regnskap AS | Professional & scientific | 2012 |
| Langbryggen 17 AS | Real estate | 2015 |
| Langbryggen 21 AS | Real estate | 1995 |
| Langbryggen Tannklinikk AS | Health & social care | 2008 |
| Langsæveien 4 AS | Real estate | 2019 |
| Langsæveien 6 AS | Real estate | 2019 |
| Langsæveien Utvikling AS | Real estate | 2000 |
| Langås Holding AS | Real estate | 2018 |
| Latakia AS | | 2026 |
| Latakia Nordic AS | Professional & scientific | 2026 |
| Laukvik Holding AS | | 2021 |
| Lauritsen 79 AS | | 2022 |
| Laursen Transport AS | Transport & logistics | 1992 |
| Lauvland Optikk AS | Wholesale & retail | 1986 |
| Lcgcards AS | Wholesale & retail | 2025 |
| LCS Holding AS | Health & social care | 2016 |
| Lege Alexander Nystedt AS | Health & social care | 2015 |
| Lege Elisabeth Bruflodt Stenhagen AS | Health & social care | 2021 |
| Lege Håvard Orlien AS | Health & social care | 2014 |
| Lege Jørn Otto Ahlqvist AS | Health & social care | 2014 |
| Legedrift AS | Health & social care | 2019 |
| Legegruppen Arendal AS | Health & social care | 2025 |
| Legro AS | Real estate | 1993 |
| Lek 1 AS | Wholesale & retail | 2016 |
| Lek 2 AS | Wholesale & retail | 2019 |
| Lek 3 AS | Wholesale & retail | 2019 |
| Lek Invest AS | Administrative & support | 2019 |
| Letterstedtska Foreningen | Other services | 2012 |
| Levende Grill Og Kaffe Arendal AS | Transport & logistics | 2019 |
| LGT Logistics | Transport & logistics | 2012 |
| Lgu for a Rainy Day AS | Real estate | 2014 |
| Lightworks AS | Professional & scientific | 2026 |
| Lille Andevinge AS | | 2015 |
| Lille Hotell AS | Hospitality | 2019 |
| Lille-Strømsbu Barnehage Ans | Education | 2015 |
| Lilleaas & Partnere AS | Financial services | 2015 |
| Lillegull's Mote Ans | Wholesale & retail | 1999 |
| Lillejord AS | | 2024 |
| Lillerolf's MC Shop AS | Wholesale & retail | 2002 |
| Linco Maskinering AS | Manufacturing | 2011 |
| Linda Samslått Holding AS | Real estate | 2022 |
| Lindebakken Barnehage AS | Education | 2005 |
| Lindstølen AS | | 2020 |
| Lindstølen Gård AS | Wholesale & retail | 2023 |
| Lindtvedt Aviation AS | Education | 2026 |
| Lindtvedt Holding AS | | 2026 |
| Lindtvedt Retail AS | Wholesale & retail | 2026 |
| Lionlight Holding AS | Information & communication | 2024 |
| Lis Garden AS | Hospitality | 2019 |
| Ljøstad Maskin AS | Construction | 2014 |
| Lob Tekstil AS | Wholesale & retail | 2021 |
| Lokalutleie AS | Other services | 2007 |
| Lokesvei Garasjelag SA | Real estate | 1983 |
| Lona Investment AS | Real estate | 2023 |
| Longum Gård AS | Administrative & support | 2023 |
| Longum Invest AS | Real estate | 2019 |
| Longum Næringsbygg AS | Real estate | 2022 |
| Longum Næringspark AS | Real estate | 1991 |
| Longum Property AS | | 1985 |
| Longum Stål AS | Wholesale & retail | 2025 |