Grandi also warned of the burden being placed on numerous world's poorest states, as some 84 per cent of the world's displaced people are living in poor and middle income countries, the BBC reported.
All in all, more than 737,000 people fled the conflict in South Sudan past year.
Around half a million other refugees were able to return to their home countries, and about 6.5 million internally displaced people to their areas of origin - although many did so in less than ideal circumstances and facing uncertain prospects.
He also called for properly protecting and caring for the world's refugees, internally displaced and asylum-seekers - who now number 22.5 million, 40.3 million, and 2.8 million, respectively.
"By any measure, this is an unacceptable number, and it speaks louder than ever to the need for solidarity and common objective in preventing and resolving crises", he said. While civil conflicts have driven many Somalis out, there have also been desperate conditions such as famines and droughts that have forced people to leave the country.
More than four million South Sudanese have been internally displaced and another two million have fled the country as refugees because of the four-year-old civil war.
For the third consecutive year, Turkey hosted the largest number of refugees worldwide, with 2.9 million people.More news: Rejecting trademarks that 'disparage' others violates First Amendment
More news: Pence reportedly hires his own outside lawyer for Russian Federation questions
More news: British prime minister names new chief of staff
South Sudan has the fastest-growing displaced population in the world after peace efforts in the country fizzled out in July.
Syria is the only country in which a majority of the population is forcibly displaced.
The 2016 report said 84,283 individuals had made donations and there had also been increasing support from business, community groups and refugee diaspora.
Figures are based on the agency's own data and on numbers reported by governments and non-governmental organizations.
Uganda needs more help from the global community in dealing with huge numbers of refugees from South Sudan, Amnesty worldwide said Monday. (These are the most recent complete numbers available.) This is a 5.8 million increase from the previous year and is the highest number of displaced persons ever recorded. The report attributed that slight reduction in part to people who had returned to their homes, offsetting the number of new people who had fled. Some 37 countries together accepted 189,300 refugees for resettlement. Lebanon, where one in six people is a refugee, continued to host the largest number of refugees relative to its national population.
Among its findings, the report noted that some 75,000 asylum claims were received from children travelling alone or separated from their parents. The war in Syria, now in its seventh year, has created a total of 5.5 million refugees as of 2016.
"At the same time, they are not adequately funding reception of refugees in poor host countries", added Jan Egeland. "Borders must be kept open, but we can not expect a country like Uganda to shoulder the entire bill", said Egeland.