Over the past few years, several U.S. tabloids have published stories linking the stars, who both practise Scientology.
During an appearance on "Watch What Happens Live", host Andy Cohen asked Elisabeth about the rumours, and "The Invisible Man" star revealed that they are untrue and have become something of a joke among her pals.
"I actually was confused and also mainly got texts from people being like, 'I didn't know, why didn't you tell me (about marrying Tom)?' And just confusion from my friends, but mainly poking fun at it 'cause obviously they knew it wasn't true," she explained.
Elisabeth was even more shocked when she saw what was supposedly a photograph of her and Tom together - as she could tell it wasn't her.
"I saw it on the cover of one of the gossip magazines, and I was like, 'I've never had that haircut'," she explained. "Like, it was supposed to be a picture of the two of us and I was like, 'I've never styled my hair like that.' "
Elisabeth did marry the actor and comedian Fred Armisen in 2009 but they separated after less than a year of marriage and divorced in 2011.