Geometric tomography is the area of mathematics dealing with the retrieval of information about a geometric object from data about its sections by lines or planes, or orthogonal projections onto lines or planes, or both. The use of the term "geometric object" is deliberately vague. A special case would be the study of sections or projections of a convex body or polytope, but it is sometimes more appropriate to consider star-shaped bodies, finite sets, compact sets, or even Borel sets.

Within mathematics, geometric tomography has links to convex geometry, integral geometry, Minkowski geometry, functional analysis, and combinatorics, and beyond mathematics, to computerized tomography, discrete tomography, crystallography, electron microscopy, computer vision, morphology, stereology, and pattern recognition.