The "huge cache" of sarcophagi, all in apparently good condition, was discovered in the city of Luxor, according to Egyptian government officials.
In an official statement, Egypt's Ministry of Antiquities said the coffins were discovered "as the ancient Egyptians left them".
Engravings and colours on the caskets were well-preserved, said officials, and could date back tens of thousands of years.
They were found in Al-Assasif, an ancient cemetery on the west bank of the River Nile, and spread out over two levels of a large tomb.
The Al-Assasif site once formed part of the ancient city of Thebes and includes tombs dating as far back to the Middle Kingdom of Ancient Egypt, or 1975 BC.
It is also close to the site of the Valley of the Kings, where for around 500 years in Ancient Egypt, tombs were made for the most powerful in society, including pharaohs.
No further details were given about form which period the coffins may date.
Officials have described the find as "one of the largest and most important discoveries to have been announced in the past few years".
They released several images showing antiquities minister Khaled El-Anany inspecting the coffins.
A press conference has been called for Saturday, when further details are expected.
It is just the latest discovery of Ancient Egypt artefacts in recent weeks.
It comes less than a week after Egyptian authorities published details of an ancient "industrial area" in the Luxor area.
This find included as many as 30 "warehouses" for workers.
Any major archaeological discoveries could also help revive Egypt's flagging tourism sector, which was badly hit by the turmoil following an uprising in 2011 and several terror attacks.