The king and his wife, Queen Camilla, were greeted by French Prime Minister Elisabeth Borne in a windy Paris, before heading to a ceremony at the Arc de Triomphe, where they paid tribute to French and British soldiers who died in two world wars.
The trip, initially planned for March, was supposed to have been Charles' first state visit abroad since becoming monarch on the death of his mother, Queen Elizabeth II. But it was shelved due to widespread rioting and strikes across France against pension reforms.
The king and Queen Camilla were welcomed at Paris Orly airport by Prime Minister Elisabeth Borne, with the visit blessed by pristine autumn clear skies, AFP reported.
They then paused to remember war dead by laying wreaths at the Arc de Triomphe monument in the capital.
The French president has dealt with no fewer than four UK premiers over the last half-decade, and has a strong personal rapport with Charles.
Charles on Thursday addresses lawmakers in the French Senate, again following in the footsteps of his mother who did the same in 2004.
Charles' visit is seen as the follow-up to moves by UK Prime Minister Rishi Sunak to reset relations between the two neighbours after post-Brexit turbulence.
Coincidentally, Charles arrives one day after Macron held talks with British opposition leader Keir Starmer, whose Labour Party is increasingly confident of being able to oust the ruling Conservatives from power.