The ceasefire deal reportedly states that the main entrances to the Syrian camp will be opened and basic services will be restored.
Nearly 18,000 people have been besieged in the Palestinian campt since last July. Rights groups say more than 100 people have starved to death.
The ceasefire is said to include the Syrian army, militant groups based in Yarmouk and many Palestinian factions, SANA news agency reported.
It is not clear when the truce will begin. However, previous truces have been broken.
Both food and medicine are in scarce supply in Yarmouk and large parts of the suburb lie in utter ruin.
For the last two weeks, the United Nation's agency for Palestinian Refugees (UNRWA) has been unable to distribute food because of continued clashes.
UNRWA spokesman Chris Gunness said the agency had received "credible information about an agreement signed yesterday between Syrian authorities and militant groups inside Yarmouk."
"We would welcome any durable and binding agreement that achieves a cessation of hostilities, full humanitarian access and an end to the suffering of civilians in Yarmouk and all of Syria," he added.
The camp, first built for Palestinians fleeing the 1948 Arab-Israeli war, became the focus of heavy fighting in late 2012 when foreign-sponsored insurgent groups infiltrated the area.
NTJ/MB