The various stages of the SKA will be capable of performing world-leading
weak gravitational lensing cosmology, both alone and in cross-correlation with other experiments such as DES and Euclid. In addition, radio wavelength surveys provide additional information which provide a potential remedy to a number of systematics which can limit optical and near-IR studies. However, weak lensing from radio
interferometers will be hard, requiring extraordinarily accurate modelling
of the morphology of large numbers of faint sources. I will give an
overview of what can be done with radio weak lensing, showing projected cosmological constraints, and discuss how we are starting to address the challenges with micro-Jy depth pathfinding experiments,
simulations of wide field surveys and the radioGREAT imaging and shear measurement algorithm competition.