| ATLANTIC HOSE 2 LLC | — | 20222313DC | 2021-07-07 | Dissolved | AUGUSTA |
| ATLANTIC HOSPITALITY MANAGEMENT, LLC | — | 20226879DC | 2021-11-16 | Active | BIDDEFORD |
| ATLANTIC HOSPITALITY, INC. | — | 19881278 D | 1987-11-30 | Suspended | PORTLAND |
| ATLANTIC HOUSE AT YORK BEACH, LLC | — | 20060211DC | 2005-07-21 | Dissolved | PORTLAND |
| ATLANTIC HOUSE BREWING COMPANY, LLC | — | 20131267DC | 2012-10-19 | Dissolved | MACHIAS |
| ATLANTIC HOUSE BY RAM SCARBOROUGH BEACH, SCARBOROUGH, MAINE 04074 TELEPHONE 207.774.9801 | — | 19880102M | — | | |
| ATLANTIC HOUSE BY THE SEA, LLC | — | 20120025DC | 2011-07-13 | Dissolved | PORTLAND |
| ATLANTIC HOUSE GRILL LLC | — | 20123599DC | 2012-05-23 | Dissolved | YORK BEACH |
| ATLANTIC HOUSE, INC. | — | 19990891 D | 1998-11-19 | Dissolved | LUBEC |
| ATLANTIC HYTTE, LLC | — | 20231597DC | 2022-03-16 | Active | SWANS ISLAND |
| ATLANTIC INCORPORATION SERVICES, INC. | — | 20130165 D | 2012-09-10 | Dissolved | GRAY |
| ATLANTIC INDUSTRIAL PIPING, INC. | — | 19951123 D | 1994-12-22 | Suspended | SCARBOROUGH |
| ATLANTIC INDUSTRIES, INC. | — | 20060975 D | 2005-12-14 | Dissolved | BANGOR |
| ATLANTIC INFORMATION PARTNERS, LLC | — | 20030539DC | 2002-09-24 | Dissolved | AUBURN |
| ATLANTIC INNOVATION, LLC | — | 20151284DC | 2014-10-03 | Active | Gorham |
| ATLANTIC INSECT & LAWN CONTROL, INC. | — | 20100287 D | 2009-10-14 | Dissolved | PORTLAND |
| ATLANTIC INSECT AND LAWN CONTROL, INC. | — | 19851526 D | 1985-03-08 | Suspended | PORTLAND |
| ATLANTIC INSULATION CORP. | — | 19942204 D | 1994-05-05 | Dissolved | PORTLAND |
| ATLANTIC INSULATION MANUFACTURING COMPANY | — | 19920116 D | 1991-07-24 | Suspended | PORTLAND |
| ATLANTIC INSULATION SERVICES, INC. | — | 19972761 D | 1997-06-18 | Active | AUBURN |
| ATLANTIC INSURANCE & BENEFITS, INC. | — | 19972316 D | 1997-04-24 | Active | BELFAST |
| ATLANTIC INSURANCE AGENCIES | — | 19860569 D | 1985-09-26 | Merged | GORHAM |
| ATLANTIC INTELLIGENCE, LLC | — | 20223163DC | 2021-08-02 | Canceled | SPRINGVALE |
| ATLANTIC INTERNATIONAL ADJUSTMENT, INC. | — | 19841437 D | 1984-03-20 | Suspended | WINDHAM |
| ATLANTIC INTERNATIONAL EMERGENCY MEDICINE INSTITUTE CORPORATION | — | 20050973 D | 2004-11-29 | Dissolved | WATERVILLE |
| ATLANTIC INTERNATIONAL MORTGAGE COMPANY | — | 19990642 F | 1999-01-05 | Withdrawn | AUGUSTA |
| ATLANTIC INVESTMENT ADVISORS, INC. | — | 19990480 D | 1998-09-14 | Active | LEWISTON |
| ATLANTIC INVESTMENT GROUP, LLC | — | 20195843DC | 2019-04-01 | Dissolved | OLD TOWN |
| ATLANTIC INVESTMENTS, INC. | — | 19851923 D | 1985-05-02 | Active | BANGOR |
| ATLANTIC INVESTORS CORPORATION | — | 19910406 F | 1991-01-30 | Withdrawn | AUGUSTA |
| ATLANTIC INVESTORS, LLC | — | 20170922DC | 2016-08-30 | Active | PORTLAND |
| ATLANTIC ITALIAN COMPANY | — | 19992149 D | 1999-05-05 | Dissolved | BOOTHBAY |
| ATLANTIC JEWELS DIRECT MARKETING CORP. | — | 19912298 D | 1991-06-24 | Suspended | PORTLAND |
| ATLANTIC KAYAK TOURS | — | 19962013 D | 1996-03-20 | Active | MACHIAS |
| ATLANTIC KINETIC WELLNESS, INC. | — | 202700020 D | 2026-07-20 | Active | WINDHAM |
| ATLANTIC KING FISHERIES II, INC. | — | 19881957 D | 1988-03-09 | Dissolved | PORTLAND |
| ATLANTIC KING FISHERIES, INC. | — | 19881416 D | 1987-12-21 | Dissolved | PORTLAND |
| ATLANTIC KITCHEN CENTER, INC. | — | 19880393 D | 1987-07-23 | Dissolved | PORTLAND |
| ATLANTIC L.E.D. AND GEAR LLC | — | 20140566DC | 2013-08-09 | Active | SWANS ISLAND |
| ATLANTIC LABORATORIES, INC. | Manufacturing | 19760102 F | 1975-11-04 | Active | WALDOBORO |
| ATLANTIC LAND COMPANY | — | 19710097 D | 1971-10-11 | Active | BANGOR |
| ATLANTIC LAND SERVICES GROUP, INC. | — | 20050388 D | 2004-08-26 | Dissolved | ELLSWORTH |
| ATLANTIC LANDSCAPE & DESIGN, INC. | — | 20041601 D | 2004-02-12 | Dissolved | PORTLAND |
| ATLANTIC LANDSCAPE CONSTRUCTION, INC. | Transportation and warehousing | 20000677 D | 1999-10-18 | Active | PORTLAND |
| ATLANTIC LANDSCAPING DEPOT, LLC | — | 20053288DC | 2005-05-05 | Dissolved | ELIOT |
| ATLANTIC LASER CLINIC, LLC | — | 20080650DC | 2007-08-31 | Dissolved | AUGUSTA |
| ATLANTIC LAWN CARE AND LANDSCAPE LLC | — | 20170792DC | 2016-08-18 | Dissolved | BREWER |
| ATLANTIC LAWN CARE, LLC | — | 20143611DC | 2014-03-21 | Active | PORTLAND |
| ATLANTIC LEADERSHIP CENTER, L.L.C. | — | 20207584DC | 2020-05-29 | Dissolved | EASTPORT |
| ATLANTIC LEADERSHIP INSTITUTE, INC. | — | 19910326ND | 1991-03-15 | Suspended | EASTPORT |