Efforts have so far failed to end the 10-month-old conflict that pits the Sudanese Armed Forces, SAF, against the paramilitary Rapid Support Forces, RSF.
Thousands of people have been killed and approximately eight million have been forced to flee their homes, making it the country with the largest displaced population in the world.
"Some of these violations would amount to war crimes," Volker Turk, the U.N. High Commissioner for Human Rights, said in a statement accompanying the report.
"The guns must be silenced, and civilians must be protected," Turk added.
Separate from the report, which investigates incidents through to December, Turk's office said on Friday that it had reviewed "credible" though unconfirmed video evidence appearing to show soldiers in army uniform parading with the decapitated heads of perceived RSF supporters while chanting ethnic slurs.
SAF said the footage was "shocking" and that it would investigate. A U.N. rights spokesperson said Turk's office would follow up with Sudanese authorities on the progress of the investigation.
The U.S. has already formally determined that the rivals have committed war crimes and said the RSF, and allied militias were involved in ethnic cleansing in West Darfur. Both sides have said they would investigate reports of killings and abuses and prosecute any fighters found to be involved.
The United Nations report is based on interviews with over 300 victims and witnesses as well as footage and satellite imagery. It says that sometimes those fleeing for their lives or displaced by the violence became victims of explosive weapons attacks.
In one incident, dozens of displaced people were killed when their camp in Zalingei, Darfur was shelled by RSF between September 14-17, the report said.
At least 26 civilians, mostly women and children, were killed on August 22 by shells reportedly fired by SAF while sheltering under a bridge.
The report also says the RSF had adopted a military strategy of using human shields, citing testimonies of victims involved.
It describes incidents in the capital Khartoum where dozens of individuals were arrested and placed outside near RSF military posts to deter air strikes from Sudanese fighter jets.
U.N. investigators have so far documented cases of sexual violence affecting 118 people, including one woman who was detained and repeatedly gang-raped for weeks. Many of the rapes were committed by RSF members, the report said.
Reuters has also documented cases of gang rape in ethnically targeted attacks by RSF forces and allied Arab militia.