SHE’S been a talk-show host, swami, psychic and, in her own words, “a glittering giga-star.”

Now Dame Edna is about to make her opera debut – with the Metropolitan Opera, no less – in a New Year’s Eve performance of “The Barber of Seville.”

Australia’s hothouse flower – embodied for the last 50 years by Barry Humphries – will appear in the second act of Rossini’s comic opera, during the music-lesson scene.

No word yet on whether the star of “Dame Edna: Back with a Vengeance” will be wearing her trademark rhinestoned spectacles – or if the sound coming from Italy is that of Rossini turning in his grave.

Tickets for “Barber” are on sale at the Met box office, through its Web site at http://www.metopera.org or by calling (212) 362-6000.