The 2020 Pacific hurricane season was a near average Pacific hurricane season in terms of named storms, featuring 17, but well below average season for hurricanes and major hurricanes, with only 4 hurricanes and 3 major hurricanes forming. Additionally, no tropical cyclones formed in the Central Pacific basin for the first time since 2017. The season officially began on May 15 in the East Pacific Ocean, and on June 1 in the Central Pacific (from 140°W to the International Date Line, north of the equator; they both ended on November 30. These dates conventionally delimit the period of each year when most tropical cyclones form in the respective regions. However, the formation of tropical cyclones is possible at any time of the year, as illustrated in 2020 by the formation of the season's first system, Tropical Depression One-E, on April 25. This was the earliest formation of a tropical cyclone on record in the eastern Pacific basin proper. The final system of the season was Tropical Storm Polo, which dissipated on November 19.

A Pacific hurricane is a tropical cyclone that develops within the northeastern and central Pacific Ocean to the east of 180°W, north of the equator. For tropical cyclone warning purposes, the northern Pacific is divided into three regions: the eastern, central, and western, while the southern Pacific is divided into 2 sections, the Australian region and the southern Pacific basin between 160°E and 120°W. Identical phenomena in the western north Pacific are called typhoons. This separation between the two basins has a practical convenience, however, as tropical cyclones rarely form in the central north Pacific due to high vertical wind shear, and few cross the dateline.