Supernovae have long been proposed to be efficient dust producers in galaxies. Observations in the mid-infrared indicate that dust forms a few hundred days after the stellar explosion. Yet, the chemical type and the amount of dust produced by supernovae are not well quantified. In this review, we summarise our current knowledge of dust formation derived from observations of supernovae, present the various theoretical models on dust synthesis and their predictions, and discuss these results in the context of the most recent observations of dust in supernova remnants.