GWS senior assistant coach Mark Williams will leave the club to take up a development role at Richmond next year after the Giants chose to extend the contract of current coach Kevin Sheedy.

The Tigers today announced the signing and Williams informed Giants management after the club's 38-point loss to North Melbounre last night.

The former Port Adelaide coach had been considered a chance to lead the Giants after Sheedy's contract expired at the end of this season after playing a major match-day and training role this year. Sheedy's new deal opened the door for other clubs, with the Tigers landing the premiership coach.

"Mark has an outstanding pedigree as a coach, in particular with the development of young players, and we're thrilled to have him join our coaching group," Richmond football manager Craig Cameron said.

"We have worked hard to build an exciting playing list over the past few years, and we believe Mark will really help add to the progression of the group."