The 1915 Galveston hurricane was a tropical cyclone that caused extensive damage in the Galveston area in August 1915. Widespread damage was also documented throughout its path across the Caribbean Sea and the interior United States. Due to similarities in strength and trajectory, the storm drew comparisons with the deadly 1900 Galveston hurricane. While the newly completed Galveston Seawall mitigated a similar-scale disaster for Galveston, numerous fatalities occurred along unprotected stretches of the Texas coast due to the storm's 16.2 ft (4.9 m) storm surge. Overall, the major hurricane inflicted at least $30 million in damage and killed 403–405 people. A demographic normalization of landfalling storms suggested that an equivalent storm in 2018 would cause $109.8 billion in damage in the United States.

Reanalyses of the Atlantic hurricane database concluded the storm formed near Cabo Verde on August 5, gradually strengthening into a hurricane as it tracked westward. However, it remained undetected by the United States Weather Bureau until it passed over the Lesser Antilles as a hurricane on August 10. The storm inflicted damage to shipping on the islands and flooded docks and streets in Martinique and Dominica. Two days later, the intensifying storm passed north of Jamaica, bringing 80–90 mph (130–140 km/h) winds to the northern coast. Significant losses were reported to the island's banana, beet, and sugar plantations, while coastal surge washed out roads and destroyed wharves; fifteen people in Jamaica were killed. Most houses and coconut trees were destroyed on Cayman Brac west of Jamaica, and substantial damage occurred across the Cayman Islands. On August 14, the hurricane clipped the western extremity of Cuba, killing fourteen. The storm's winds were estimated at 145 mph (230 km/h)—a Category 4 hurricane on the modern-day Saffir–Simpson hurricane wind scale; this was ultimately the hurricane's peak intensity.

Over the Gulf of Mexico, the hurricane caused 101 deaths, mostly from the sinking of the steamer Marowjine in the Yucatán Channel. During the early morning hours of August 17, the hurricane made landfall with winds of 130 mph (210 km/h) at San Luis Pass, Texas, approximately 26 mi (42 km) southwest of Galveston. Much of coastal Texas was affected by the storm's rough surf, with a total death toll of 275. Cities along Galveston Bay were inundated by storm surge, destroying entire towns and damaging numerous buildings. Galveston was largely protected by its seawall, but the strong waves caused extensive beach erosion that undermined 200 outlying homes. Ninety percent of homes outside the protection of the seawall on Galveston Island were destroyed. Most buildings in Houston were impacted, incurring $1 million in damage. The storm brought strong winds and torrential rainfall across East Texas, causing widespread cotton losses and damage to infrastructure—the highest rainfall total from the storm was 19.83 in (504 mm) in San Augustine, Texas.

The hurricane weakened as it tracked farther inland, degenerating into a tropical storm within a day of its landfall in Texas. A northeast curve soon followed, resulting in a track into the Ozarks and Ohio River Valley; the storm transitioned into an extratropical cyclone on August 20 over the Ozarks and dissipated over the Gulf of Saint Lawrence three days later. Heavy rainfall and significant river flooding occurred along the storm's path during this latter phase of its evolution. Levee breaches in along the White River in Arkansas and the Mississippi River in Illinois flooded entire towns. St. Louis, Missouri recorded its rainiest 24-hour period in history, experiencing a deadly flood of the River Des Peres and Meramec River that impacted much of the city and surrounding suburbs, killing 20 people and destroying over a thousand homes.