Hannover Re (in German Hannover Rück) is a reinsurance company based in Hannover, Germany. It is the third-largest reinsurance group in the world, with a gross premium of around €33 billion. Founded in 1966, Hannover Re transacts all lines of property & casualty and life & health reinsurance and has a network of over 170 subsidiaries, branches and representative offices on all five continents with a total staff of more than 3,000. The Group's German property and casualty business is written by the subsidiary E+S Rück.

Hannover Re was founded on 6 June 1966.

In the 1970s, the company entered the US and Japanese markets. In 1981, the company made its first acquisition of a foreign insurance group – the Hollandia Group (now Hannover Re Group Africa). In 1990, the acquisition of Hamburger Internationale Rückversicherungs-AG followed.

In 1994, Hannover Re went public. In the same year, the company was the first reinsurer ever to securitise natural catastrophe risks for the capital market.

In 1996, Eisen und Stahl Rück was integrated into the Hannover Re Group. From then on, Hannover Re serves foreign insurance markets, while Eisen und Stahl Rück – now E+S Rück – takes responsibility for handling the German property and casualty market.

As part of its increasingly international orientation, the legal form of the company was conversed to a Societas Europaea (European Company) in 2013. Hannover Re has since traded as Hannover Rück SE.

In 2025, Clemens Jungsthöfel succeeded Jean-Jacques Henchoz as Chief Executive Officer of Hannover Re.

Hannover Re transacts reinsurance in the business groups Property & Casualty and Life & Health.