The 2015 North Indian Ocean cyclone season was an event in the annual cycle of tropical cyclone formation. The North Indian Ocean cyclone season has no official bounds, but cyclones tend to form between months of April and December, with the peak from May to November. These dates conventionally delimit the period of each year when most tropical cyclones form in the northern Indian Ocean.

The 2015 Atlantic hurricane season was the last of three consecutive below average Atlantic hurricane seasons. It produced twelve tropical cyclones, eleven named storms, four hurricanes, and two major hurricanes. The Accumulated Cyclone Energy (ACE) for the season was 68% of the long-term median value. The hurricane season officially began on June 1, 2015, and ended on November 30, 2015. These dates historically describe the period each year when most tropical cyclones form in the North Atlantic basin. However, the first named storm, Ana, developed on May 8, nearly a month before the official start of the season, the first pre-season cyclone since Beryl in 2012 and the earliest since Ana in 2003. The formation of Ana marked the start of a series of seven consecutive seasons with pre-season activity, spanning from 2015 to 2021. The season concluded with Kate transitioning into an extratropical cyclone on November 11, almost three weeks before the official end.