Mathematical logic is the study of formal logic within mathematics. Major sub-areas include model theory, demonstration theory, set theory, and recursion theory. Research in mathematical logic usually addresses the mathematical properties of formal logical systems, such as their expressive or deductive power. Mathematical logic has several commonly used meanings.

It originally referred to symbolic or formal logic, and later came to be associated with the study of the logical (and even philosophical) foundations of mathematics. In contemporary use by mathematical logicians, the term refers to several branches of pure mathematics whose study involves careful attention to formal axiom systems and formal definability. The divisions between these areas, along with the divisions between mathematical logic and the rest of mathematics, are not entirely clear, as many areas of research and methods are overlapping and mutually reinforcing. This category has the following 32 subcategories, out of 32 total.

The following 200 pages fall into this category, out of a total of approximately 202. This list may not reflect recent changes.