Dai Young has left Wasps after nine years as director of rugby.
It was announced last week that the 52-year-old Welshman would "step back" from first-team duties at the club but his departure has now been confirmed.
Wasps, who are 10th in the table after 10 games, were Premiership runners-up in 2017 but never won a major trophy during Young's tenure, which overlapped the move from High Wycombe to Coventry.
Young said that it was "the right time for both the club and myself" to part.
"It will be tough to leave a club and group of people that has meant so much to me over the past decade," added Young. "It has been a fantastic experience for myself and my family."
Young's son Thomas, 27, remains at the Ricoh Arena as one of the Premiership club's two co-captains.
Attack and backs coach Lee Blackett, 37, who was appointed last week as interim head coach, stays in charge, having taken over for the first time prior to Saturday's defeat at local rivals Leicester Tigers.
Blackett's backroom team now consists of defence coach Ian Costello, forwards coach Andy Titterrell, transition coach Matt Everard and assistant attack coach Martin Gleeson ,the former St Helens, Warrington, Wigan and Great Britain rugby league international.
Young's nine years with Wasps
Former dual code Wales international Young, who went on three separate Lions tours, and won three caps, in 1989, retired as a player with Cardiff Blues in 2002.
He led Wasps to the Premiership play-offs three years in succession between 2016 and 2018, including an extra-time Twickenham final defeat by Exeter in 2017, as well as to the last eight of the European Champions Cup three times, when they were also narrowly denied - by Saracens in 2017.
But the Coventry-based outfit have lost a lot of their big names, including England back Elliot Daly's move to Saracens last summer, to follow the loss of World Cup winner Willie Le Roux, Kurtley Beale, Danny Cipriani, James Haskell and Christian Wade.
In all competitions, they have won only 13 of their last 47 matches, during which time they have been knocked out of Europe early in each of the past two seasons.
Following Saturday's seventh defeat in 10 Premiership games this season, they are just two points above 11th-placed Leicester.
But, with Saracens' relegation already confirmed following their salary cap breaches, Wasps are spared any concerns of dropping down to the Championship.
"I'd like to place my sincere thanks on record to Dai for his hard work and support over the years," said chairman Derek Richardson.
"He has done a tremendous job. In particular, I'd like to thank him for his advice and help when I first became involved with the club, and also his support for the move to Coventry in 2014."