Nobel laureate Françoise Barré-Sinoussi was one of 563 honourees announced on Sunday, along with scholars, economists, athletes, artists and public servants.
Barré-Sinoussi discovered HIV as the cause of AIDS in 1983, which led to a Nobel Prize in medicine in 2008.
She is currently the head of the international AIDS society, and has previously spoken out against the Catholic Church’s stance against the use of condoms in preventing the spread of the disease.
Non-French and naturalised citizens are also eligible, allowing Brooke and Costa-Gravas to get the gong.
Also on the list was Christian Prudhomme, director of the Tour de France.
That honour comes as the Legion's council reviews the case of disgraced American cyclist Lance Armstrong.
Armstrong joined the order in 2005, long before he admitted to doping in order to win seven Tour championships.
The Order of the Legion of Honour was established in 1802.
French first consul and de-facto military dictator Napoléon Bonaparte believed citizens deserved an order of merit to replace an outdated order of nobility.
The honourees are announced three times a year.