The development of electronics is increasingly dependent on low-cost, flexible, solution-processed semiconductors. Colloidal quantum dots are solution-processed semiconducting nanocrystals that have a size-tunable bandgap and can be fabricated on a range of substrates. Here we review developments in colloidal quantum dot electronics, focusing on luminescent, optoelectronic, memory and thermoelectric devices. We examine the role of surface chemistry in the suppression of non-radiative processes, the control of light–matter interactions and the regulation of carrier transport properties. We also highlight the prospects of perovskite quantum dots as single-photon sources, the design of new classes of colloidal quantum dots and superlattices for emerging applications and the role of hybrid device architectures in compensating for the limited carrier mobility in colloidal quantum dot solids while maintaining their tunable spectral response.