The statue of the powerful and renowned monarch who ruled Egypt over 3,000-years-ago and was found close to Ramses II's temple in the ancient city of Heleopolis.
Egypt's antiquities ministry said it is one of the most important historical finds in the country.
"Last Tuesday they called me to announce the big discovery of a colossus of a king, most probably Ramses II, made out of quartzite," Antiquities Minister Khaled al-Anani told Reuters on Thursday.
Archaeologists pulled the statue's head out of a pool of water as local residents, reporters and government officials looked on.
"We found the bust of the statue and the lower part of the head and now we removed the head and we found the crown and the right ear and a fragment of the right eye," Anani said.
The team, which is comprised of experts from Egypt and Germany - also found the upper part of a life-sized statue of Pharoah Seti II - Ramses II's grandson.
Heliopolis' sun temple was founded by Ramses II, which is why experts have inferred that the statue is of him.
The temple was one of Egypt's largest, however, was destroyed in the Greco-Roman period. A number of its obelisks were then moved to Alexandria and even Europe, while stones were also stolen for use in Cairo building sites.
|The eight-metre statue was discovered in Cairo's Matariya district [AFP]|
With the large parts of the statues now out of the water, experts will attempt to extract the remaining pieces in order to restore them.
If the larger find is confirmed to depict Ramses II, it will be displayed at the entrance of the Grand Egyptian Museum, which is set to open in 2018.
Ramses II, also known as Ramses the Great, was the third monarch of the Nineteenth Dynasty of Egypt and ruled from 1279 to 1213 BCE.
He is famed for having led several military expeditions and for expanding his empire to stretch from modern day Syria to Nubia.
Thursday's haul could prove to be a huge blessing for Egypt's struggling tourism industry, which has suffered since the overthrow of Hosni Mubarak in 2011. Tourist numbers in 2011 slumped to 9.8 million from over 14.7 million in 2010.
Adding to Egypt's tourism woes has been the threat of terrorism. In October 2015, a Russian commercial airliner travelling from the resort of Sharm el-Sheikh carrying 224 people was brought down, which the Islamic State group claimed was from a bomb its militants planted onboard the aircraft.
The attack dealt a further blow to visitor numbers, which dropped to 1.2 million in the first quarter of 2016 from 2.2 million in the previous year.