Swedish geologist Ulf Erlingsson claims Ireland closely matches a description of the sunken island made by ancient Greek philosopher Plato.
Both islands are 300 miles long, 200 miles wide and widest over the middle.
He also claims the island that was actually sunk was Dogger Bank in the North Sea, which was hit by a flood-wave over 8,000 years ago.
Erlingsson also points out a few more similarities between the two.
Both have a central plain, which is fringed by mountains.
He also claims the capital of Atlantis is Tara, the legendary seat of the high king of Ireland in County Meath.
Other theories say Atlantis could have been in the Aegean Sea.