The 1909 Atlantic hurricane season was an average Atlantic hurricane season. The season produced thirteen tropical cyclones, twelve of which became tropical storms; six became hurricanes, and four of those strengthened into major hurricanes. The season's first storm developed on June 15 while the last storm transitioned into an extratropical cyclone on November 14. The most notable storm during the season formed in late August, while east of the Lesser Antilles. The hurricane devastated the Lesser Antilles, the Greater Antilles, and Mexico, leaving around 4,000 fatalities and more than $50 million (1909 USD) in damage.

The Atlantic hurricane season is the period in a year, from June 1 through November 30, when tropical or subtropical cyclones are most likely to form in the North Atlantic Ocean. These dates, adopted by convention, encompass the period in each year when most tropical cyclogenesis occurs in the basin. Even so, subtropical or tropical cyclogenesis is possible at any time of the year, and often does occur.