Liebig's Law of the Minimum is a law in agricultural science formulated by Justus von Liebig. It states that growth is limited not by the total resources, but by the scarcest resource. It was originally applied to plant or crop growth. It was found that increasing the amount of a nutrient in plenty did not increase growth. Only by increasing the amount of the nutrient that was most scarce was growth of the plant or crop improved.

Liebig's Law has been extended to biological populations. The growth of such a population is not limited by the total amount of resources throughout the year, but by the minimum amount of resources available to that population at the time of the year of greatest scarcity. As an example, the growth of a population of rabbits might depend not on how much food was available in the summer but rather on how much food was available in the winter.