Gossip blogs suggested the former Friends star and Theroux became engaged in March (12) and they had been scouting for the perfect location to exchange vows during a recent visit to the Mediterranean country.
Aniston had allegedly settled on a luxury hotel on the island of Crete, where her actor father John Aniston was born, and editors at TMZ.com went as far as to name July (12) as the month of their ceremony.
But a spokesperson for Aniston has debunked the claims, telling GossipCop.com the story is a "fabrication".
The rep adds that the report is likely a "placed ad for the hotel" to boost publicity for its exclusive wedding packages.
Aniston and Theroux began dating last year (11) after meeting on the set of romantic comedy Wanderlust.
Ironically, the actress' ex-husband Brad Pitt recently announced his engagement to his longtime partner Angelina Jolie.