Available diffraction tomography algorithms are based on Fourier transform techniques and require either plane‐wave illumination in a uniform background medium or far‐field illumination combined with paraxial approximations. In this paper a generalized diffraction tomography algorithm is introduced that can handle both irregularly spaced measurement data, nonuniform background models, and general aquisition geometries. Using data from water tank experiments, the method’s ability to yield high‐quality reconstructions of geometry and velocity, as long as the weak‐scattering assumption is satisfied, is demonstrated.