An off-season South-West Indian Ocean tropical cyclone is a tropical cyclone that exists in the South-West Indian Ocean basin outside of the official tropical cyclone season. The World Meteorological Organization currently defines the season as occurring between November 15 and April 30, of the following year, with the exception for Mauritius and the Seychelles, for which it lasts through May 15 rather than April 30. As of 2024, there have been at least 113 tropical cyclones known to have occurred off-season. Cumulatively, at least 165 deaths occurred due to the storms, and the most recent off-season storm was Cyclone Ialy in May 2024.

This list is incomplete; you can help by adding missing items. (July 2023)

The wind speeds listed are maximum ten-minute average sustained winds, while the pressure is the minimum barometric pressure, both of which are estimates taken from the archives of either Météo-France, the Australian Bureau of Meteorology, the Fiji Meteorological Service, and New Zealand's MetService. If there are no known estimates of either the winds or pressure then the system is listed as "Not specified" under winds or pressure, if there is no known estimated winds or pressure. For deaths and damages "None" indicates that there were no reports of fatalities, although such storms may have impacted land. The damage totals are the United States dollar of the year of the storm.

Systems