Abstract: In this talk, I will give an overview of tetrahedron instantons. I will describe the construction of tetrahedron instantons in string theory and in noncommutative field theory. The tetrahedron instanton partition function lies between the higher-rank Donaldson-Thomas invariants on Calabi-Yau threefolds and fourfolds, and can be computed exactly. It admits a free field representation, suggesting the existence of a novel kind of symmetry which acts on the cohomology of the moduli spaces of tetrahedron instantons. Tetrahedron instantons can also be used to study the duality between type IIA superstring theory and M-theory.