Ptychography, a scanning coherent diffractive imaging method, produces super-resolution quantitative images with phase and absorption contrast. Phase contrast provides morphological information and is exceptionally useful in the hard X-ray imaging regime where absorption is comparatively weak. High contrast ultrastructure images can be obtained even from single-component specimens. However, for thicker samples with complex morphology, phase contrast imaging with nanoscale resolution may be insufficient to yield scientific insights due to the projection of the three-dimensional (3D) structure into a single plane. Ptychographic X-ray computed tomography (PXCT) produces richly detailed volumetric images, reconstructed from projections of the sample or from a full 3D dataset, which provide a means to non-destructively investigate 3D nanostructures. This presentation will review the development of PXCT over the past decade, including complementary extensions such as simultaneous PXCT and X-ray fluorescence microscopy (XFM), with applications in the biomedical and materials sciences.