Selfridges beer, wine and spirit buyer Dawn Davies is leaving the post after nine years.
Davies told harpers.co.uk that she had a new position in the drinks arena to go to but was unable to reveal what at this stage.
She added: "I'm a bit terrified because I'm leaving the best job in the world, but hopefully to go to the new best job in the world.
"I'm not leaving because I don't love Selfridges but just because it was time for a new challenge and I didn't want to become stale.
"If I were to move up the ladder at Selfridges it would mean moving away from the product - and the product is what it's all about for me.
"I'm really passionate about it and don't want to lose that."
Davies said she expected to be doing consultancy "on some level" for Selfridges until a successor was fully on board.
Before joining the upmarket retailer Davies had an extensive career as an on-trade manager and sommelier with Zuma, Boxwood, The Sqaure and The Ledbury.
During her time at Selfridges, its drinks department won several industry awards. Davies oversaw a radical revamp of the deaprtment in 2013.
Davies will leave Selfridges on August 14 and the post has been advertised.