The find was made earlier this week during an excavation at Les Varines.
The archaeological digs, which have been supported by Jersey Heritage, are part of the ‘Ice Age Island’ project designed to find out more about Jersey’s prehistoric past.
Dr Matt Pope, a senior research fellow of the Institute of Archaeology at University College London, said that the find could be significant in discovering more about the Island’s history.
He added that the find was unusual in that part of the Island as although mammoth remains have been uncovered in Jersey before, they have mainly been in St Brelade and not in St Saviour.
‘Most of the finds at Les Varines have largely been stone tools and artefacts – not bones,’ Dr Pope said.
‘Mammoths are quite rare on the Island outside of St Brelade and mammoths would have been quite close to extinction in this part of the world at this time.’
He added that during the Ice Age, Jersey would have been connected to the rest of Europe and hunter-gatherer groups may have followed large animals, such as mammoths, to the area.
The excavation at Les Varines will continue until the end of August and after that the bone will be properly analysed and lab-tested.
Dr Pope added: ‘It is so fragile that we can’t really handle the object too much.
‘It is only because it is such a large tooth bone that it has survived. It is not going to be until we get it into a laboratory and x-ray it that we can definitively say what it is.
‘The find gives an added picture of what the landscape would have been like at the time it was occupied. Now we know that man was sharing the land with mammoths and it opens up the possibility of some interesting studies into the interactions between the two species.’
He added: ‘We have lifted the possible tooth in a block of sediment and our specialists will be able to x-ray it and see whether it can be cleaned up and removed from the block once we have finished the dig.’
A special open day at the site will be held on Sunday 20 August.