Sima Zhao's regicide of Cao Mao

Sima Zhao's regicide of Cao Mao, also known as the Ganlu Incident (Chinese: 甘露之變), occurred on 2 June 260 in Luoyang, the capital of the state of Cao Wei, during the Three Kingdoms period. Cao Mao, the nominal emperor of Wei, attempted to oust the regent Sima Zhao, who effectively controlled the Wei government. However, the plot concluded with Cao Mao's death and Sima Zhao retaining his status. Contrary to its intention, the coup actually increased the Sima clan's power and influence in Wei, albeit at the cost of Sima Zhao's personal standing, thus providing a foundation for the eventual usurpation of the Wei throne in February 266 by Sima Zhao's son Sima Yan, who founded the Western Jin dynasty.

The incident is also mentioned in the historical novel Romance of the Three Kingdoms by Luo Guanzhong, which dramatises the history of the late Eastern Han dynasty and the Three Kingdoms period. The events of the incident described in the novel are largely similar to that described in historical sources.