In 2018, domestic extremists killed at least 50 people in the U.S., a sharp increase from the 37 extremist-related murders documented in 2017, though still lower than the totals for 2015 (70) and 2016 (72). The 50 deaths make 2018 the fourth-deadliest year on record for domestic extremist-related killings since 1970.

The extremist-related murders in 2018 were overwhelmingly linked to right-wing extremists. Every one of the perpetrators had ties to at least one right-wing extremist movement, although one had recently switched to supporting Islamist extremism. White supremacists were responsible for the great majority of the killings, which is typically the case.