Fundamental law(s) may refer to:

Organic law, in particular,

Constitution, in particular,

The Russian Constitution of 1906

The German Grundgesetz (more commonly translated as "Basic Law")

The four individual laws that together make up the Constitution of Sweden

The Fundamental Laws of England

The Fundamental Law of Vatican City State

The Fundamental Law of Hungary

The Basic Laws of a country that does not use the term "constitution" or has an uncodified constitution

Any of the fundamental physical laws of the universe

In Abrahmic religions, The Ten Commandments