Severe Tropical Storm Ampil, known in the Philippines as Severe Tropical Storm Inday, was a tropical cyclone that caused moderate damage in the Ryukyu Islands and East and Northeast China in late July 2018. The tenth named storm of the annual typhoon season, Ampil developed into a tropical depression east of Luzon on July 17. The system gradually strengthened over the following days amid a marginally favorable environment and became a severe tropical storm late on July 19 as it moved northwest. Maintaining its strength, Ampil passed over Okinawa Island from July 20 to 21. Thereafter, Ampil weakened slightly while crossing the East China Sea, before making landfall in Shanghai, China, on July 22. The system weakened slowly over land and degraded to a tropical depression on July 23. The system turned eastwards as it continued weakening over land, diminishing to a remnant low on July 25 and dissipating fully a day later over the Russian Far East.

Tropical cyclones and subtropical cyclones are named by various warning centers to simplify communication between forecasters and the general public regarding forecasts, watches and warnings. The names are intended to reduce confusion in the event of concurrent storms in the same basin. Once storms develop sustained wind speeds of more than 33 knots, names are generally assigned to them from predetermined lists, depending on the basin in which they originate. Some tropical depressions are named in the Western Pacific, while tropical cyclones must contain a significant amount of gale-force winds before they are named in the Southern Hemisphere.