Kate Middleton is 'less than pleased' with Prince William's ski trip behaviour
During the two-day trip, the couple will meet survivors of the 2015 terror attack on the Bataclan concert hall in Paris as well as President Francois Hollande.
The two-day trip could be seen as a bid to help smooth out global relations between Britain and the rest of the European Union, which have become increasingly frosty in recent months.
The dancing royal was in Verbier, Switzerland for a ski trip with his friends.
Before departing London for Paris, William and Kate attended a traditional St. Patrick's Day event to honor the Irish Guards.
They discussed the French-British relationship in the context of Britain's forthcoming departure from the European Union.
The couple is reportedly staying at the British ambassador's residence during their visit.
The royals will launch a initiative called "Les Voisins" (The Neighbours), celebrating relations between France and Britain.
The embassy also hosted a dinner for the couple with guests including British actress Kristin Scott Thomas, French actor Jean Reno and former French footballer Robert Pires.
William has travelled privately to the French capital in the past - including with his brother Prince Harry - but there are no plans for him and the duchess to visit the Pont de l'Alma tunnel or the Flame of Freedom memorial close to where his mother died. The most popular royal couple on the planet comes for a 48-hour official visit to our attractive capital.
Princess Diana, her boyfriend Dodi Fayed, and their driver Henri Paul died in a crash at the Pont de l'Alma on August 21, 1997.
Also, Charles, Will and younger son Prince Harry will travel to France on April 9 (Charles' and Camilla's 12th wedding anniversary) to attend the commemorations for the 100th anniversary of the WWI Battle of Vimy Ridge, Canada's most notable military victory and a symbol of Canadian national pride.
Numerous stories led with the claim that William had undertaken 13 days of royal duties in 2017, far fewer than the 24 performed by the queen and four less even than his brother, Prince Harry.
The Royal couple's trip comes just a few days after the Duke was criticised for his "dad-dancing" on the dance floor at a Swiss nightclub and for missing a major Commonwealth celebration with the Queen.
Last year, the Prince worked on royal engagements for a total of 80 days - the same number as his 90-year-old grandmother the Queen.