She takes over from Shay Segev with immediate effect after Segev announced he was leaving Entain after just six months in the role to join sports streaming platform, Dazn.
Nygaard-Andersen was previously the chief executive for the EMEA region at Swedish media giant, Modern Times Group, and has been a non-executive director of Entain since December 2019.
She becomes the first female to lead a UK-listed gambling company.
She said: “I am very excited to have the opportunity of continuing the extraordinary momentum that Entain has in its existing markets, as well as helping it enter new regulated markets and reach new audiences.
“I am deeply wedded to Entain’s commitment to providing industry-leading levels of player protection, and to its philosophy that the most sustainable business in our industry will be the most successful business in our industry.”
Barry Gibson, Entain chairman, said: “We are extremely fortunate to have such an outstanding candidate and readymade CEO in Jette.
“She is already deeply immersed in Entain’s strategy, and clearly shares our ambition to be the world leader in sports betting and gaming entertainment.”
Entain recently rebranded from GVC Group and is renowned for its commitment to safe gaming and responsible gambling.
It is a member of the Betting and Gaming Council, an industry body that looks to set the highest possible standards for operators – read our interview with BGC chairman, Brigid Simmonds.
This is the second major gambling industry appointment in as many weeks after gambling addiction charity, GambleAware, named Zoë Osmond as its new CEO.