McGeechan has been director of rugby at Wasps since 2005
Ian McGeechan has quit as director of rugby at Wasps.
The 62-year-old, who will lead the Lions this summer, has been linked with a role at London Scottish but could yet be handed a consultancy role at Wasps.
He had been at Wasps for four years, leading them to Guinness Premiership and Heineken Cup triumphs, but they will end this season trophy-less.
"We are discussing the format of my involvement next year to ensure a successful transition," said McGeechan.
"I have had four incredible years at Wasps and developed many special and significant friendships with fellow coaches and players and I am proud of the club's achievements in winning three major trophies during that time.
"Wasps and its people will always remain very close to my heart."
McGeechan's departure had been widely expected and Wasps owner Steve Hayes paid fulsome tribute to the coaching legend.
"Geech has been a loyal servant to the club and he is a man who I have a huge amount of respect for," he said.
"We thank Geech for his massive contribution over the last four years, helping us to secure an impressive collection of silverware.
"He leaves with our best wishes and enormous thanks. He will be remembered as a key member of the Wasps coaching dynasty.
"As he prepares to travel to South Africa for the Lions tour we wish him the very best of luck with the series."
Wasps are reported to be on the verge of announcing that Tony Hanks, a New Zealander who is in charge of Waikato, will be their new director of rugby.
Shaun Edwards, who will be McGeechan's defence coach for the Lions, is expected to remain as the club's head coach.
Hanks has had two stints with Wasps, including a four-month spell this season when he was called in as cover for McGeechan, who has been overseeing preparations for the Lions tour to South Africa.
The former Scotland coach took over from Warren Gatland as Wasps director of rugby in 2005 and the club has won the Guinness Premiership, Heineken Cup and EDF Energy Cup under his control.
But this season has been a disappointment and they will qualify for the Heineken Cup only if Northampton lose to Bourgoin in the Challenge Cup final next week.
McGeechan is now expected to take a more low-profile role at London Scottish, who have been promoted to the third tier of English rugby for next season and are eager to make a quick ascent to the Premiership.