Bet365 chief executive Denise Coates was paid a total of £421m last year, newly-released annual accounts for the gambling firm reveal.
Ms Coates, already Britain’s highest-paid boss, saw her package increase from £277m the year before.
She also owns more than 50% of the company entitling her to a chunk of the £95m dividends the company paid out.
The £421m pay package is more than 5,000 greater than that of the prime minister.
Bet365’s annual report said: “The group ensures that remuneration for all employees is appropriate and fair, and is reflective of the individual’s input and contribution to the business as well as the overall performance of the group.”
The company’s results, which covered the year to 29 March 2020, were affected by the “dramatic” impact of the COVID-19 pandemic at the end of the period which resulted in the global sporting calendar grinding to a halt.
That helped push revenues down 8% to £2.81bn and together with “an increase in remuneration and other costs” contributed to an 83% slump in pre-tax profits to £137m.
One of the factors weighing on the bottom line was the £87m loss incurred by Championship football club Stoke City, which Bet365 owns.
The company report said that the board had decided at the outset of the pandemic to guarantee until the end of August 2020 not to make any pay cuts or redundancies in its workforce.
Directors also pledged not to make any use of government support including the furlough scheme.
Bet365 also donated £85m during the year to the Denise Coates Foundation, a charity, which has previously made grants to causes including health, education and disaster relief.
Ms Coates said in the report that the business had made “significant progress” including investment in a “safer gambling” initiative.
“The period also saw the initial impact of COVID-19, with sport at all levels halted across the world,” she added.
“I am delighted with how the group responded and adapted to these challenging circumstances.
“We continued to operate the business successfully throughout the lockdowns with business continuity plans enacted resulting in staff being able to work from home whilst significant investment was also made to ensure the office environments were COVID secure.”
Bet365 was founded in a car park in 2000 and has grown rapidly to become a global online sports betting giant, employing more than 5,000 people and boasting of 53 million customers worldwide.
Ms Coates’s pay package was criticised by Luke Hildyard, director of the High Pay Centre.
He said: “It’s appallingly inefficient for single individuals to hoard wealth in this way when more progressive policies on taxation, intellectual property ownership or profit sharing could re-direct it towards better public services or raising living standards for low and middle income earners.”
Ms Coates was the country’s largest taxpayer for the second year running, according to the latest annual Sunday Times Tax List. She and her family, who are worth more than £7bn, had a tax liability of £573 million last year, it reported.