Williams joined the pub in May 2018 with the intention to split his time between the Cotswolds and his Michelin-starred London restaurant Alyn Williams at The Westbury.
But he has now returned to the capital to focus on his Mayfair hotel restaurant full time.
“I had a brilliant time with the team at The Wild Rabbit and we’ve ended on extremely amicable terms, but London is where my heart really lies," says Williams in a statement.
"I’ve got an exceptionally talented kitchen brigade at The Westbury and I’m hugely excited for this new chapter.”
The Wild Rabbit was opened by Daylesford Organic founder Lady Carole Bamford in 2013 and was named Michelin Pub of the Year in 2015.
It won a Michelin star in the 2017 edition of the guide under chef Tim Allen, but lost the accolade in the 2018 red book following his departure.
Nathan Eades, former head chef at Michelin-starred Simpsons in Birmingham, has headed up the kitchen since December 2017.