The new figure brings the total number of people currently living in internal displacement due to violence to 41.3 million, an all-time high, according to a report by the Internal Displacement Monitoring Centre (IDMC) and the Norwegian Refugee Council (NRC).
Thousands of Nigerian refugees still fear Boko Haram violence (2:29)
"It is really a mind-boggling figure," NRC chief Jan Egeland told reporters in Geneva.
"It takes extreme violence and fear of disasters to force a family out of their home, their land, their property, their community."
Including those uprooted from their homes by natural disasters as well as conflicts, a total of 28 million people were displaced internally in 2018, the report said.
A full 10.8 million new internally displaced people (IDPs) last year were fleeing conflict, with strife in the Democratic Republic of Congo (DRC) and Syria, as well as intercommunal tensions in Ethiopia, Cameroon and Nigeria responsible for most of the displacements, the study said.
The number of people currently living as IDPs is far higher than the some 25 million who have fled across borders as refugees.
Countries with most IDPs
Surprisingly perhaps, the report found that the highest number of new internal displacements last year was in Ethiopia, with a full 2.9 million people fleeing their homes inside the East African country, where communal clashes, typically sparked by land disputes, are common.
Strife-torn DRC came in second, with 1.8 million new IDPs in 2018, followed by Syria with 1.6 million new internal displacements.
In total, Syria, ravaged by eight years of war, counts 6.1 million IDPs, in addition to around the same number of Syrians still living as refugees.
On top of those forced from their homes by violence, 17.2 million people were internally displaced by natural disasters last year, the report found.
Tropical cyclones and monsoon floods forced nearly 10 million to flee within the Philippines, China and India.
IDMC chief Alexandra Bilak told reporters that most of those displacements were linked to government-orchestrated evacuations ahead of natural disasters.
"This, of course, saves lives, but demonstrates that there are still too many people in those countries who are exposed to extreme events," she said.
In the United States, hundreds of thousands of people were forced from their homes in California last year by the most destructive wildfires in the state's history.
Some 22,000 people remain displaced by those fires, Bilak said.