Hurricane Tammy was a long-lived Atlantic hurricane in October 2023 that caused minor impacts across the Leeward Islands and Bermuda. The nineteenth named storm and seventh hurricane of the 2023 Atlantic hurricane season, Tammy originated from a late-season tropical wave off the coast of West Africa that developed into a tropical storm on October 18. Tammy became a hurricane two days later, unusually late in the season for hurricanes to develop in the tropical Atlantic. and continued to intensify, aided by record warm sea surface temperatures. The hurricane then made landfall on Barbuda the next day. Afterwards, the hurricane slowly moved northwest paralleling the Leeward Islands, remaining steady in intensity for several days. On October 25, as the system began to accelerate northeast ahead of an approaching trough, Tammy intensified and peaked as a Category 2 hurricane with maximum sustained winds of 110 mph (175 km/h). It maintained hurricane strength for five days, before weakening to a tropical storm. Tammy degenerated into a post-tropical cyclone on October 28.

The 2023 Atlantic hurricane season was the fourth-most active Atlantic hurricane season on record with 20 named storms forming, tied with 1933. Among them, 7 became hurricanes, with 3 reaching major hurricane strength. The season also had an above‑normal accumulated cyclone energy (ACE) rating of 148, despite the presence of the 2023–24 El Niño event, which typically results in less activity, and had the most storms for an El Niño year on record, largely due to record-warm sea surface temperatures across the Atlantic. The season officially began on June 1 and ended on November 30. These dates, adopted by convention, historically describe the period in each year when most tropical cyclogenesis occurs in the Atlantic. However, the formation of subtropical or tropical cyclones is possible at any time of the year, as demonstrated by the formation of a subtropical storm on January 16, the earliest start of an Atlantic hurricane season since Hurricane Alex in January 2016. At the time, the system was assessed as non-tropical by the National Hurricane Center (NHC), resulting in it staying unnamed.