- April 2015 president wanted run for a third term
- announcement sparked protests
- government shut down internet and telephone communications, closed universities
- May 2015 coup planned by military
- fighting has killed thousands and left more displaced
The actor, known for his roles in Oceans 11, Gravity and The Monuments Men, presented the the Aurora Prize to Marguerite Barankitse.
The Burundian Catholic woman has offered shelter and sanctuary to thousands of orphans in the central African country.
According to The Catholic Herald George, Clooney said that Marguerite Barankitse should inspire people to stand up for those in need.
She was presented with almost £800,000 ($1.1 million) as part of the Aurora Prize.
It recognised an individual's work towards humanitarian causes and Armenian philanthropists selected her for the award.
George Clooney said: "By recognising Marguerite Barankitse's courage, commitment and sacrifice, I am hopeful that she can also inspire each one of us to think about what we can do to stand up on behalf of those whose rights are abused and are in most need of our solidarity or support."
He went on, saying that it was a "reminder of the impact that one person can have even when encountering seemingly insurmountable persecution and injustice."
Barankitse, 59, began started working in Burundi during the civil war in the 1990's.
Three of the four final nominees for the Aurora Prize were Catholic.
Also in the running was Fr Bernard Kinvi, a priest who saved 1,500 Muslims from slaughter in the Central African Republic, Dr Tom Catena, the only surgeon for 750,000 people in the Nuba Mountains in Sudan and Syeda Ghulam Fatima, who works to end bonded labour in Pakistan.
