Dionisio Alcalá Galiano (October 8, 1760 – October 21, 1805) is a Spanish naval officer, cartographer, and explorer.
He maps various coastlines in Europe and the Americas with unprecedented accuracy, using new technology such as chronometers.
He commands an expedition that explores and maps the Strait of Juan de Fuca and the Strait of Georgia, and makes the first European circumnavigation of Vancouver Island.
He reaches the rank of brigadier and dies during the Battle of Trafalgar.
He sometimes signs his full surname, Alcalá-Galiano, but often uses just Galiano.
The published journal of his 1792 voyage uses just the name Galiano, and this has become the name by which he is most known.