Emma Weymouth flashed her abs in a chic polka dot bikini as she departed Le Club 55 in St Tropez on Tuesday.
The Marchioness of Bath, 38, stunned in her stylish beachwear as she was seen heading back to her yacht on a boat after dining at the celebrity hotspot.
She wore a halterneck bikini top and matching semi-sheer shirt, teamed with black-rimmed sunglasses.
Emma accessorised her beachwear with a huge straw hat tied around her neck and shielded her eyes with a navy baseball cap.
The beauty enjoyed a day out in the south of France with her husband Ceawlin Thynn and their two young children John, Viscount Weymouth, and Lord Henry Thynn.
Emma and Ceawlin married at their stunning home Longleat in June 2013 and welcomed their first child John, in October 2014.
On her wedding day, Emma became the first black marchioness in British history.
Following a pregnancy struggle, the couple welcomed their second child, a son Henry, via a surrogate in Los Angeles in December 2016.
The boys' official titles are The Honourable John Alexander Ladi Thynn and The Honourable Henry Richard Isaac Thynn.
At the time, Emma told the Daily Mail: 'We are simply ecstatic. His arrival has completed our little family and brought us so much happiness.'
Ceawlin added: 'Never did I imagine that in West Hollywood I'd become father to John's little miracle baby brother.
'It's a wonder of modern science that the Longleat Bath family has been completed (for now at least) by Emma and I having a much-loved son, helped so crucially by a tremendous surrogate in California, to extend our family.'
Last year the couple purchased a property in West London once lived in by Winston Churchill for £18.5 million.
The Grade II-listed home was bought from a multi-millionaire divorcee whose former husband's Nazi-supporting grandfather was convicted at the Nuremberg trials.
Churchill lived there on-and-off from 1945 until his death - inside his bedroom - in 1965 at the age of 90 after suffering a stroke.
The grand home was last put on the market in 2016 for £28 million after undergoing extensive renovations.
