The probabilistic method is a powerful technique, pioneered by Erdos,by which one proves the existence of a combinatorial object by showing that an attempt to produce such an object randomly will succeed with positive probability. Often this argument will lead to an efficient algorithm to construct the desired object. In this talk, we will survey several applications of this technique to graph colouring. We will see how to prove that under certain conditions, a graph has a colouring meeting some desireable properties, by showing that a simple randomised procedure to construct such a colouring will succeed with positive probability. Much of the work described here is joint with Bruce Reed.