The 2019–20 South-West Indian Ocean cyclone season was a slightly above-average season in tropical cyclone and subtropical cyclone formation west of 90°E. The season officially began on 15 November, however, the formation of the first system—Zone of Disturbed Weather 01—occurred on 22 July 2019, well before the official start of the season. This was the earliest start to a season since the 2016–17 season. The season then officially ended on 30 April 2020, with the exception of Mauritius and the Seychelles, for which it officially ended on 15 May 2020. These dates conventionally delimit the period of each year when most tropical and subtropical cyclones form in the basin, which is west of 90°E and south of the Equator. Tropical and subtropical cyclones in this basin are monitored by the Regional Specialized Meteorological Centre in Réunion.

The 2019–20 South Pacific cyclone season was a slightly above-average season in which tropical cyclones formed within the South Pacific Ocean to the east of 160°E. The season officially ran from November 1, 2019, to April 30, 2020, however a tropical cyclone could form at any time between July 1, 2019, and June 30, 2020, and would count towards the season total. The season began on November 22 with the formation of Tropical Cyclone Rita, which would later become a severe tropical cyclone. The season has been near-average in terms of activity, with 8 tropical cyclones and 4 severe tropical cyclones forming during the season. The season featured Cyclone Harold, the first Category 5 severe tropical cyclone in the basin since Cyclone Gita, and one of the strongest since Cyclone Winston. During the season, tropical cyclones are officially monitored by the Fiji Meteorological Service (FMS), Australian Bureau of Meteorology (BOM) and New Zealand's MetService. The United States Armed Forces through the Joint Typhoon Warning Center (JTWC) also monitors the basin and issue unofficial warnings for American interests. The FMS attaches a number and an F suffix to tropical disturbances that form in or move into the basin while the JTWC designates significant tropical cyclones with a number and a P suffix. The FMS, BoM and MetService all use the Australian Tropical Cyclone Intensity Scale and estimate wind speeds over a period of ten minutes, while the JTWC estimated sustained winds over a 1-minute period, which are subsequently compared to the Saffir–Simpson hurricane wind scale (SSHWS).