The Ladbrokes and Coral owner has agreed a deal with the Crown Prosecution Service (CPS) to pay £585m after a bribery investigation.
Entain is paying the sum following a Bribery Act investigation by HM Revenue & Customs (HMRC) into its former Turkish business.
Under investigation were activities of suppliers and former employees of the Entain group of companies.
In particular, HMRC was looking at the alleged failure of the company to have adequate bribery prevention measures.
The more than half a billion pound financial penalty will be paid £20m to charity and £10m to HMRC and the CPS to cover their costs.
The firm’s chairman, Barry Gibson, said: “This legacy matter concerns a business which was sold by a former management team six years ago.”
He said the group “has changed immeasurably since these events took place”.
“We are committed to continuing our journey towards operating only in regulated markets, and are now widely recognised as a best-in-class, responsible operator with the highest levels of corporate governance across all aspects of our business,” he added.
The agreement on Friday received preliminary judicial approval. Final approval will be sought on 5 December.
Once final approval is given the payment will be made in four instalments.
Entain said in a market update on the London Stock it has “co-operated extensively with HMRC and the CPS and will continue to co-operate with the authorities into the future”.
It sold the Turkish business in 2017, before Coral and Ladbrokes were acquired. Entain was in negotiations on the fine and had set aside the sum in August.
HMRC launched the probe in 2019.