Guillaume Joseph Gabriel de La Landelle (born 5 March 1812, in Montpellier; died 19 January 1886, in Paris) was a French naval officer, journalist, and writer, a seafaring novelist, and author of other maritime works. He was also one of the pioneers of aeronautics. He served in the navy and authored several novels that depict maritime customs and naval warfare.
His project for the steam helicopter served as inspiration for Jules Verne's engine in his novel Robur le Conquérant (Robur the Conqueror).
He was also involved with aeronautics. Nadar, who had been enthusiastic about aviation since 1858, founded the (roughly translated as: Society for the Promotion of Air Locomotion with the Aid of Machines Heavier Than Air) together with Gabriel de La Landelle in 1863 and began building a giant balloon, aptly named Le Géant (The Giant). Its first flight took place in Paris on 4 October 1863, with 13 people on board, including Jules Verne.