Fanny Hugill, 93, from Fairford, Gloucestershire, was awarded the Chevalier de l'Ordre National de la Legion d'Honneur.
She was in Admiral Bill Tennant's team that planned the Normandy landings.
"We did know how momentous a day it was but of course all the planning had been done so no one was nervous," she said.
"We all had a job to do."
Ms Hugill said she was "very, very honoured" to have been recognised.
She joined the Women's Royal Navy Service (Wrens) in 1942 and worked initially as typist and then a plotter, who would chart and plot the routes of all the vessels that went through the English Channel.
"We ran up and down ladders and plotted the courses on a large map with chinagraph pencils," she said.
She was then commissioned as a 3rd Officer to Admiral Bill Tennant, who planned the Normandy landings before returning to her role as a plotting officer.
She was in the Ops Room during the night and morning of the 5 and 6 June 1944 when D-Day took place.
It was announced on the 70th anniversary of D-Day that the Legion d'honneur would be awarded to all veterans who took part in the invasion.
The ceremony at the Mercure in Bristol on Wednesday was organised by Blind Veterans UK, of which she is a member.
A blind war veteran has been awarded France's highest military honour for her part in liberating the country during the Second World War.