William Hill's chief executive Philip Bowcock is to stand down later this month and will be replaced by the group's chief digital officer as it leads a push online and overseas.
The group, which employs 1,300 people in Leeds, said Mr Bowcock will step down on September 30 after three years as chief executive.
He is being replaced by Ulrik Bengtsson, who joined William Hill in April last year and has been overseeing the group's fast-growing digital operations.
Mr Bengtsson becomes chief executive-designate with immediate effect.
William Hill said Mr Bowcock will remain with the group until the end of the year to help ensure a smooth handover.
The firm added that the changeover at the top was part of its succession planning and was "consistent with the group's strategy of becoming a digitally led and internationally diverse gambling company".
It comes after William Hill last month revealed that half-year profits were cut by almost half after the bookmaker was hammered by the Government crackdown on fixed-odds betting terminals (FOBTs) and heavy investing in the US.
The group is also in the middle of widespread betting shop closure programme, having announced plans to shutter 700 bookies across the UK, putting 4,500 jobs at risk.
William Hill's chairman Roger Devlin said Mr Bowcock has "led the business through a period of unprecedented change including the challenges of the Triennial Review and has set a clear strategy, driven our expansion in the US and reinvented our approach to safer gambling".
He said Mr Bengtsson was "ideally suited to lead our next phase of growth".
"Ulrik has deep understanding in digital and has the international and sector experience we need to deliver on our strategy," he said.
In August, William Hill reported a 47 per cent plunge in adjusted pre-tax profits to £50.8m for the six months to July 2019, after it was hit by the change in minimum stake.
Mr Bowcock said he has presided over "an intense period with the industry and business experiencing significant structural and regulatory change".
"Having recruited and worked with Ulrik for the last year and a half, I am confident he will take advantage of the opportunities ahead and we will see William Hill go from strength to strength," he said.