Multiphase ceramics and composites generally contain a hard phase embedded in a creeping matrix. The hard phase can occupy a wide range of volume fraction. The creep behaviour depends on the nature of percolation in the material. Below the threshold for point-contact percolation, particles are independent, and the creep viscosity is increased due to the rheology of matrix flow around the particles. Above the threshold for facet-contact percolation, particles are locked in place and only limited movement involving rearrangement of the soft phase around the particles is possible. This is the case with glass-bonded ceramics such as silicon nitride. At intermediate volume fractions, a deformable network is developed. This is the case for most whisker-reinforced ceramics. A set of mechanistic models has been developed for each of these regions. They are found to give reasonable predictions about the creep behaviour of real materials.