The club will now begin looking for a replacement for the Australian.
“It is with a heavy heart that I have today agreed the release of James Webster from his position of head coach,”said Trinity chairman Michael Carter.
“James rescued us last season from the threat of relegation and for that I am truly thankful. I wish James and his family every success and happiness in the future, and thank him for all his hard work in his 4 years here.
“We will now be conducting the search for a new Head Coach. In the interim, Stuart Dickens will take charge of first team affairs, until we can make an appointment.”
Webster himself felt that the time was right to depart.
“I felt now was the right time to allow someone else the opportunity to take the team forward,” he said.
“In taking this decision my hope is it will allow the club to fulfil its goal and remain in Super League.
“I would like to thank both Michael and Chris for the opportunity and wish everyone at the Wildcats the best for the future.”