Fort Julien (or, in some sources, Fort Jullien) was a fort in Egypt, originally built by the Ottoman Empire and occupied by the French during Napoleon Bonaparte's campaign in Egypt and Syria between 1798-1801. It stood on the left bank of the Nile a couple of kilometres north-east of Rashid (Rosetta) on the north coast of Egypt.
The fort was a low, squat fortification with a central blockhouse that overlooked the final few kilometres of the Nile before it joins the Mediterranean Sea. It had been built in the 15th century by the Mamluk Sultan Qait Bey, who also built the eponymous Citadel of Qaitbay in Alexandria. The French took possession of it on 19 July 1799, only a few days before the Battle of Abukir, and embarked on a hasty rebuilding of the dilapidated fort. It was subsequently reconstructed in a more thoroughgoing fashion and was renamed Fort Julien after Thomas Prosper Jullien, one of Napoleon's aides-de-camp. Lieutenant Pierre-François Bouchard uncovered the famous Rosetta Stone at the fort while repairing its defences. Qait Bey's engineers had apparently brought it to the site from elsewhere, possibly a temple at nearby Sais, to use as fill.
Two years later, the fort was captured by a combined British and Turkish force after a short siege and bombardment.