The Answer
Yes, there are 2. Sort of.
Antarctica
Large parts of Antarctica are claimed by as many of 12 different countries. Many of these claims overlap, but there is a large block of land in Antarctica that remains unclaimed.
The Antarctic Treaty of 1961 establishes that Antarctica be used for peaceful and scientific purposes. It acknowledges the (overlapping) claims that had existed prior, to the treaty, but prohibits additional claims.
The unclaimed land is called Marie Byrd Land.
Bir Tawil Triangle
This is a small piece of land between the southern border of Egypt and the northern border of Sudan. Both countries claim that the border goes around this piece of land, but haven’t formally laid claim to the land itself.
Bir Tawil’s unusual status – wedged between the borders of two countries and yet claimed by neither – is a byproduct of colonial machinations in north-east Africa, during an era of British control over Egypt and Egyptian influence on Sudan.
Welcome to the land that no country wants – Mar 2016 – The Guardian
Essentially, in the late 19th century the British – in the colonial wisdom – wrote up a document which drew the border in a straight line between Egypt and Sudan. Three years later another document was drawn up that drew the border lower down at Bir Tawil to encompass a local tribe with greater ties to Egypt than Sudan.
Neither country is willing to claim the land, because to do so would give up other disputed land to their neighbour. It remains officially unclaimed to this day.