Stuart Law to take over as Middlesex coach from next season: English county
The former Australia batsman has signed a four-year deal and will begin duties in January following West Indies' tours of India and Bangladesh.
"It is a great privilege to be asked to coach Middlesex and to accept one of the plum jobs in world cricket," Law said.
"There is never a good time to leave but the opportunity to work with Middlesex for four years at the home of cricket was too good to decline."
After brief stints in charge of Sri Lanka and Bangladesh, the 49-year-old took over the Windies' reins in January 2017 and led his team to a memorable Test victory over England at Headingley last summer.
Law said his time in charge of the Windies had been "very enjoyable" "I believe we have made tremendous strides forward as a team during the past two years," he said.
West Indies director of cricket Jimmy Adams said: "While I regret his leaving and the timing of it, I fully understand his reasons, and along with everyone at Cricket West Indies want to thank him for his dedication and commitment whilst in the role and wish him the very best of luck at Middlesex."