The Guiding Principles, and their access to remedy pillar in particular, are grounded in a recognition of the need for rights and obligations to be matched to appropriate and effective remedies when they are breached. Concerns have been expressed by human rights observers and stakeholder groups about serious deficiencies in the implementation by many States and business enterprises of their respective international obligations and responsibilities as regards access to remedy. In 2014, OHCHR launched the Accountability and Remedy Project in response to those concerns and in order to strengthen accountability and access to remedy in cases of business-related human rights abuse. The access to remedy pillar of the Guiding Principles refers to three categories of remediation mechanisms in such cases, and the first three phases of the Project focused on how to enhance the effectiveness of these mechanisms: I: Judicial mechanisms; II: State-based non-judicial grievance mechanisms; III: Non-State-based grievance mechanisms. This work was requested and subsequently welcomed by the Human Rights Council through successive resolutions from 2014 to 2020. At the conclusion of each phase of the Accountability and Remedy Project, major reports were submitted to the Human Rights Council, detailing key observations on the functioning of these mechanisms and providing technical guidance for enhancing their effectiveness, drawing on good practices identified during the Project. The content of the present interpretative guide, which focuses specifically on the access to remedy pillar of the Guiding Principles, draws heavily from Accountability and Remedy Project reports and the extensive empirical research, stakeholder consultations and expert reviews that informed them. The guide brings together in one place the key concepts, underlying principles and learning points from the many years of work that led up to the Guiding Principles themselves, the findings from the Accountability and Remedy Project, and the reports and recommendations of the Working Group on business and human rights. The purpose of the present guide is to provide additional background explanation on the principles of the access to remedy pillar of the Guiding Principles on Business and Human Rights so as to support a full understanding of their meaning and intent. This is an interpretive guide, meaning that it clarifies how the content of the Guiding Principles should be understood. It is not an operational manual that will explain how to put the Guiding Principles into practice. Rather, the guide provides an overview of the access to remedy pillar, explains the key principles and concepts that underpin it, and addresses some common misconceptions. The guide is complemented by a set of compilations of guidance from the Accountability and Remedy Project, which provide recommended actions for enhancing the effectiveness of the different types of remedial mechanisms relevant to resolving cases relating to business and human rights. Numerous other operational tools have been developed since the endorsement of the Guiding Principles, including targeted and theme-based guidance published by OHCHR and the Working Group on business and human rights. In addition, other organizations continue to develop their own approaches, focusing on implementation of the access to remedy pillar. It is hoped that this guide will assist them in doing so by explaining further the intent behind the Guiding Principles as regards access to remedy. Ensuring access to remedy demands action from many different kinds of actors, both State based and non State based. While “effective judicial mechanisms are at the core of ensuring access to remedy”, many other kinds of mechanisms and actors also play an essential role in complementing and supplementing the vital work of law enforcement bodies, prosecutors and courts. It is hoped that, by highlighting the different ways in which these diverse actors may contribute to access to remedy, the present guide will encourage further policy innovation, for example by fostering a greater understanding of the value of coordinated action between different types of actors and mechanisms and of the conditions under which this can take place.