A power system stabiliser (PSS) for a wind turbine employing a doubly fed induction generator (DFIG) is presented. The PSS signal is added at the interface of the DFIG controller and the converter, facilitating its application and implementation on any basic DFIG control scheme. The PSS considered is based on a slip signal, but it could employ any DFIG variable influenced by network oscillations (e.g. rotor speed, stator electrical power or network frequency). Time domain simulation and eigenvalue analysis, carried out on a simple generic network model developed in Simulink that is considered representative of the major areas of the UK electricity system, is used to demonstrate PSS capabilities. It is shown that the employment of a PSS can substantially enhance the contribution of a DFIG-based wind farm to network damping and dynamic stability.