Charlotte Bankes - one of the world's leading snowboard cross athletes - has defected from the French national team and joined the British set up.
Bankes, who was born in Hemel Hempstead and moved to France at the age of four, has competed for her adopted nation at the last two Winter Olympics.
The 23-year-old claimed three World Cup medals for France last season.
But, she has opted to race for Britain leading into the next Olympics - Beijing 2022.
The snowboarder will make her GB debut at a Europa Cup event in Austria next week.
Although Bankes has competed internationally for France since the age of 15, her eldest brother Thomas has represented Great Britain and it is understood Charlotte has been considering switching for a few years.
The move was made possible earlier this week after the French Ski Federation agreed to release her registration and the International Skiing Federation (FIS) subsequently approved the request.
The news coincides with a rebranding of the British national set up which is changing its name from the 'British Ski and Snowboard' to 'GB Snowsport'.
As part of the changes the British Parasnowsport team - featuring Paralympic medallists Menna Fitzpatrick, Millie Knight and Kelly Gallagher - will be brought into the same system as their Olympic counterparts.
The organisation's CEO Vicky Gosling says the move will help enable the British set up achieve their mission of becoming one of the world's top-five snowsport nations by 2030.
"We have the coaching staff, the athletes and the support staff to make Great Britain a leading snowsport nation," she said.
"No-one should doubt our ability to achieve our vision."