In mathematics, tautness is a rigidity property of foliations. A taut foliation is a codimension 1 foliation of a closed manifold with the property that every leaf meets a transverse circle.
- <math>\mathcal{F}</math> is taut;
- there is a flow transverse to <math>\mathcal{F}</math> which preserves some volume form on M;
- there is a Riemannian metric on M for which the leaves of <math>\mathcal{F}</math> are least area surfaces.