This paper presents recent research on the application of the cone penetration test to site characterisation and foundation design. Aspects considered related to characterisation include the interpretation of relative density in granular soils, the derivation of the penetration-velocity characteristic, corrections for shallow penetration and scale effects in laboratory experiments and the influence of particle size on penetration resistance. In relation to foundation design, the paper outlines the nature of CPT-based correlations and describes the development of three types of such correlations for footings, axially loaded piles and laterally loaded piles.