This PRIO Paper examines global trends in conflicts between 1989 and 2021 using data from the Uppsala Conflict Data Program (UCDP). 54 state-based conflicts were recorded in 2021, resulting in nearly 85,000 deaths. Many of these deaths were related to the conflicts in Yemen and Afghanistan. The conflict in Yemen escalated from 2,300 deaths in 2020 to more than 23,000 in 2021. Conflicts involving the Islamic State (IS) continued throughout several regions in 2021, totalling 15 individual conflicts. State-based conflicts in Africa and Asia experience a higher rate of recurrence than other regions, which may point towards underlying incompatibilities and grievances not yet resolved by conflict parties. Non-state conflicts stabilized at higher levels than previously recorded; 76 in 2021. Battle-related deaths from non-state conflicts increased by more than 2,000 in 2021 to a total of 25,247. One-sided violence also increased in 2021, most of which is perpetrated by non-state actors. Fatalities resulting from one-sided violence numbered 10,003 in 2021. In addition, this report examines trends in non-violent movements and conflict-related sexual violence.