Third-party funding existes since the Middle Ages and was, until recently, labeled as a criminal offense in common law countries. In the last twenty years third-party funding has developed to unprecedented proportions and represents one of the world's largest markets where third-party investors offer financing of court and arbitration proceedings in exchange for compensation. This led to the development of law in the in common law countries in such a way that in most of these countries third-party funding is no longer considered a criminal offense and is allowed. In civil law countries this institute is mostly not recognized and not regulated, so it does not come as a surprise that the European Union is planning to regulate it. Third-party funding affects the procedural position of the parties and raises many questions because, although the third party is not a party to the procedure, it is interested in the outcome of the dispute it finances. Supporters of third-party funding point out that this institute enables parties who do not have financial means to access justice that they otherwise would not be able to achieve. Although in principle this is the correct position, the question is whether this is the best way to achieve access to justice, i.e. the right to a fair trial arising from the Article 6.1 of the Convention for the Protection of Human Rights and Fundamental Freedoms. In accordance with the above, the paper analyzes third-party funding in civil and arbitration proceedings from the theoretical aspect and from the aspect of case-law developed by courts and tribunals in court and arbitral proceedings.