The 75-year-old Irving, who was banned from Germany for 10 years, plans to attend a Sept. 10 meeting where attendees will pay $119 to hear him speak, The Local.de reported Tuesday.
Green Party manager Volker Beck said he got in touch with Berlin hotels when he learned of Irving's planned speaking engagement.
Most of the large downtown hotels that belong to the German hotel association are boycotting Irving. However, smaller guesthouses might take his reservation.
Irving was extradited from Germany in 1993 after being convicted of insulting the dead for denying that thousands of people died in the gas chambers at Auschwitz.
A ban against entering Germany until 2022 was lifted in March.