Fox, who joined Halfords from Walmart’s Canada unit, has been at the cycling and car parts retailer for three and a half years and is regarded by some as being instrumental in helping drive its turnaround.
Fox, who also spent a decade in various roles at Asda, will not be directly replaced and her duties will be shared across other executives, Retail Week understands.
In a statement, Halfords said: “We have been reviewing the business to ensure that it’s fit for purpose and supports our Moving Up A Gear strategic priorities.
“As a result, we have made the decision to flatten our senior structure, with Emma Fox leaving the business by mutual agreement to pursue opportunities elsewhere.”
It is not immediately clear if Fox has another role lined up, but last year she took on a non-executive role at pubs giant Punch Taverns.
“A significant loss”
An industry source told Retail Week: “I think she is a significant loss to that business and a hard act to follow.
“She was responsible for 200 people in three countries and a big driver behind their current performance.”
It also understood Fox helped orchestrate Halfords’ high-profile tie-ups with Orla Kiely, Bradley Wiggins and Chris Boardman.
Halfords boss Jill McDonald has been driving change at the retailer through its ‘Moving up a Gear’ strategy – which has included a bid to understand its customers more using data.
Last month, Halfords unveiled a better-than-expected 7% rise in third-quarter like-for-likes, but warned it will have to raise its prices due to Brexit. In its half-year, profits plunged as it felt the impact of a weak pound.