The Maritime Labour Convention, 2006, (MLC, 2006) was adopted 23rd February 2006 by the 94th International Labour Conference (ILC) of the International Labour Organization (ILO). The MLC, 2006 sets out minimum requirements concerning working and living conditions for the world s 1.2 million seafarers and the shipowner has the overall responsibility to ensure that the conditions for seafarers are fulfilled and respected onboard. The shipowners responsibility for the crew and their conditions on board vessels is not a new invention introduced by the MLC, 2006. Historically, the shipowner was the owner and the operator of the ship and the employer of its seafarers. Today, the term shipowner is used in a variety of situations as the globalization in the shipping industry has opened for new organizational structures. Ship registration practice to a larger degree facilitates imperfect transparency and even anonymity of the shipowner, making it difficult for seafarers – and authorities - to reach the shipowner in case of an incident or a breach of right. Seafarers needed a single named person to relate to. In addition, this person should be easily identifiable and being the actual person responsible for fulfilling seafarers rights. This thesis is concerning the legal definition of the term shipowner in the MLC, 2006.