Federal Common Law

Federal common law refers to judge-made law that is created by federal courts to fill gaps or address issues in areas where there is no applicable federal statute or regulation. It is a body of law developed by federal courts to govern certain matters of national concern.

In the United States, the Constitution grants Congress the power to create federal laws, and these laws generally apply uniformly across the country. However, there are situations where federal statutes may not cover a particular issue or provide clear guidance. In such cases, federal courts may create common law to provide legal rules and principles.

Federal common law can arise in various areas, such as maritime law, international law, federal contracts, federal tort claims, and constitutional law. It is important to note that federal common law is limited to the specific context or subject matter in which it is developed and does not extend to areas traditionally governed by state law.

The Supreme Court's decision in Erie Railroad Co v Tompkins (1938) significantly restricted the application of federal common law in diversity cases. The Court held that federal courts should not create general common law rules in diversity cases but should instead apply state law unless there is a specific federal law on the matter. This decision emphasised the importance of state law and the role of state courts in shaping legal principles within their jurisdictions.

Since the Erie decision, federal common law has been relatively limited, and federal courts primarily rely on federal statutes, regulations, and the Constitution to decide cases. The principle of adhering to state law in diversity cases, known as the Erie doctrine, has been a fundamental aspect of the federal judiciary's approach to resolving legal disputes.
Back to blog

UOL Case Bank

Upon joining, you become a valuable UOL student and gain instant access to over 2,100 case summaries. UOL Case Bank is constantly expanding. Speed up your revision with us now.

Subscribe Now

Where are our students from?

Yale University
Council of Europe
Baker Mckenzie 
University of Chicago
Columbia University
New York University
University of Michigan 
University College London (UCL)
London School of Economics (LSE)
King’s College London (KCL)
University of London
University of Manchester
University of Zurich
University of York
Brandeis University
University of Exeter
University of Sheffield
Boston University
University of Washington
University of Leeds
University of Law
Royal Holloway, University of London 
Birkbeck, University of London
SOAS, University of London
University of Kent
University of Hull
Queen’s University Belfast
Toronto Metropolitan University
Hong Kong University of Science and Technology
University of Buckingham

  • Criminal Practice

    Diagrams and Charts

    Our carefully designed diagrams and charts will guide you through complex legal issues.

  • Criminal Law

    Clear and Succinct Definitions

    Key concepts are concisely defined to help you understand legal topics quickly.

  • Property Law

    Statutory Provisions

    Statutory provisions are provided side by side with legal concepts to help you swiftly locate the relevant legislation.

  • Public Law

    Case Summaries

    We have summarised important cases for you so that you don't need to read long and boring cases.

  • Evidence

    Rules and Exceptions

    Rules and exceptions are clearly listed so that you know when a rule applies and when it doesn't.

  • Company Law


    Legal terms and key concepts are explained at the beginning of each chapter to help you learn efficiently.

  • Case Law

    Case law is provided side by side with legal concepts so that you know how legal principles and precedents were established.

  • Law Exam Guide

    Law Essay Guide

    You will learn essential law exam skills and essay writing techniques that are not taught in class.

  • Law Exam Guide

    Problem Question Guide

    We will show you how to answer problem questions step by step to achieve first-class results.

  • Conflict of Laws

    Structured Explanations

    Complex legal concepts are broken down into concise and digestible bullet point explanations.

  • Legal System and Method

    Legal Research

    You will learn legal research techniques with our study guide and become a proficient legal researcher.

  • Jurisprudence and Legal Theory


    All essential concepts, principles, and case law are included so that you can answer exam questions quickly.