M
- M.A. Ray & Sons
- M. Carl (Dampsk Heimdal)
- M.G. Amsinck
- M. G. Livanos
- M. Nissen (Acties, Dampk, Atalanta)
- M. Thorvik
- N. V. Scheepvaart Maatschappij Suriname, Paramaribo.
- MacAndrews & Co. Ltd.
- MacFarlane & Lander
- Macleay River Co-operative Steamship Co.
- Madrigal Shipping Co., Inc.
- Maersk Line (A. P. Møller)
- A. P. Møller / Maersk Line
- Mahieu Transports Pétroliers
- Mail Steamship Co.
- Maine Steamship Co (Portland Line)
- Makino Koreo
- Malaysian International Shipping Corporation
- Mallory Line (New York & Texas Steamship Co)
- Malmö Bogser
- Malmoil
- Malmros Rederi AB
- Mamenic Line
- Mamitank London Ltd.
- Mammoet
- Man Cheung Yuen Shipping Co.
- Manchester Lines, Ltd.
- Manchester Ship Canal Co. Ltd.
- Manhanset Line (T. Hogan & Sons)
- Mann, MacNeal & Co.
- Mannesmann Demag Material Handling Corp.
- MANZ Line
- Marítima Nacional Ltda., Companhia.
- Marchartering S. L.
- P. D. Marchessini & Co.
- Netherlands Maritime Agencies (Rotterdam) / Marco Shipping Netherlands
- Mardorf Peach & Co., Ltd
- Marfret
- Marine Transport Corporation
- Marine Transport Lines
- Maritima, Cia. de Navegação (NETUMAR)
- Maritime Co. of the Philippines
- Maritime Shipping & Trading Co., Ltd.
- AB Maritime
- Compagnie Maritime Belge
- Société Maritime et Coloniale
- Marius Nielsen & Son
- Schiffahrts und Befrachtungs Kontor Marker GmbH
- Marmara Transport A.Ş.
- Mars Steamtugs
- Compagnie Marseillaise de Navigation Coloniale
- Martı Denizcilik T.A.O.
- Martin Olsen
- Mason & Thompson
- Masurier
- Matarazzo, Sociedade Paulista de Navegação
- Sociedade Paulista de Navegação Matarazzo
- MATCO Tankers (U. K.) Ltd
- Mathiasen’s Tanker Industries
- C. Mathisen
- Loucas G. Matsas Salvage and Towage Maritime Company
- Matson Navigation Co.
- Matsuda Seiichi
- O. Mauran, New York
- Maurel & Prom
- E. J. B. Mavroleon (Bray Shipping Co., Ltd.)
- Mayflower SS Corp.
- McAllister Bros. Inc.
- McAsphalt Marine Transport Ltd
- McCallum, Orme & Co
- McCormick Steamship Co
- McIlwraith McEacharn & Co. Proprietory Ltd.
- McIlwraith McEacharn Ltd.
- McKeil Marine Ltd
- McLean’s Roylen Cruises Pty. Ltd.
- McLean's Roylen Cruises Pty. Ltd.
- McMekan, Blackwood & Co.
- Med Pacific Express
- Mediteranska Plovidba Korcula
- Mediterranean & New York Steamship Co.
- Mediterranean Steamship Co.
- Mehmet Kaptanoglu T.A.Ş.
- Meiji Kaiun K. K.
- Meimon Car Ferry K. K.
- Melbourne Steam Ship Co.
- Melbourne Steamship Co.
- Meldrum & Swinson (Essex Line, Limited)
- Melsom & Melsom
- Mems Rederi AB
- Mentz, Decker & Co. KG
- Mentz, Decker & Co. KG
- Per Henriksen (Mercandia Shipping)
- Mercantile Steamship Co.
- Merchants and Miners Transportation Co.
- Merchants Express Line
- Merchants Line for New Orleans
- Merchants Line for Washington
- Mercury Ship Management
- Mercury Shipping Co.
- Compagnie Méridionale de Navigation
- Compagnie des Messageries Maritimes
- Messieurs Louis Bureau & Fils
- Metcalf Motor Coasters Ltd.
- Metcalfe, Simpson & Co.
- Metro Meat Ltd.
- Metropolitan Coal & Oil Co.
- Metropolitan Steamship Co.
- Metz Container Line
- Mexico Shipping and Trading Company
- P. Meyer
- Michael Murphy, Limited
- Michalinos Maritime & Commercial Company, Ltd.
- Micronesian Ocean Lines
- Midgard AG & Co. KG
- Compañía Argentina de Navegación / N. Mihanovich Ltda.
- Mihei Shipping & Trading
- Mijnster
- Miller & Richards
- W. S. Miller & Company
- Mineralölwerke Albrecht & co
- Minoltra
- Minuano Navegação S.A.
- Misener Holdings Ltd.
- Mississippi Shipping Co. (Delta Line)
- Mitsubishi Kaiun K. K.
- Mitsui O. S. K. Lines.
- Mitsui Senpaku K. K.
- Miwa Asajiro
- Compagnie de Navigation Mixte
- Miyachi Kisen K. K.
- Miyama Kinroku
- Mme Régny née Bernadac
- Mo & Domsjo A/B
- Mobil Corporation (and its corporate predecessors)
- Mobil Shipping and Transportation Co.
- Moerman Kustvaart
- Mogul Line Ltd.
- Mogul Steamship Company, Limited
- A. P. Møller (Maersk Line)
- A. P. Møller / Maersk Line
- Mols-Linien A/S
- Moltzaus Tank Rederi A/B
- Monarch Steamship Co.
- Rederi AB Monark
- Monroe Brothers
- G. T. Monsen
- Montemar, S. A.
- W. Montgomery & Co., Ltd.
- Montship Lines Ltd.
- Moore & Co.
- Moore-McCormack Co.
- Mooremack’s Gulf Line
- Moore-McCormack Co. (Mooremack)
- A. J. Gonçalves de Moraes, Lda.
- Moran Towing and Transportation Company
- Møre og Romsdal Fylkesbåtar
- E. A. Moreira, Agentes de Navegação, S. A.
- Morel, Ltd.
- Moreton Tug & Barge Co. Pty. Ltd.
- Morgan & Cadogan Limited
- Morgan Line (Southern Pacific Steamship Company) (1934)
- Morgan Steamship Company (1905)
- A. J. Morland
- Morning Express
- Société Anonyme La Morue Française
- Moses Taylor
- Moss Hutchinson Line, Ltd.
- H. E. Moss & Co.
- A/S Mosvolds Rederei
- Motala Rederi Akt.
- Motortank
- Mountwood Shipping Company, Ltd.
- Compagnie de Navigation à Vapeur Claude Mourou
- Theunis (Muller)
- Willem Muller Zeesleepdienst
- Mullion & Co., Ltd.
- Multinational Ship Management Inc
- Multraship
- Multratug
- Munson Steamship Company
- Murphy (S) Palgrave Ltd. (Holland Ireland Line)
- Murray, McNab & Co.
- Murray Steamship & Tourist Co. Pty. Ltd.
- Naviera Murueta S. A.
- Mutualista Açoreana de Transportes Marítimos, S. A.
- Myanmar Five Star Line
- Myrstens Rederier
- Mystic Steamship Company (later Mystic Steamship Division of Eastern Gas & Fuel Associates)
Anything below
this line was not added by the editor of this page.