The "Friends" actress told People magazine that reports of her engagement to the "Be Cool" actor, including an article in Us Weekly, are false, calling the stories "insane."
"I'm not engaged, and I don't have a ring, and I haven't been proposed to," Aniston, 37, told People, according to an article appearing on the magazine's Web site Wednesday.
Us reported in an Aug. 9 cover story citing anonymous sources that Vaughn had proposed to Aniston on June 27 on a private jet after a trip to Mexico. Us is sticking by its story, which other media outlets picked up.
"Us Weekly based its story on lengthy interviews with four separate and independent sources close to the couple, including two who learned of the engagement directly from Vince Vaughn," the magazine said in a statement Wednesday. "Jennifer's publicist never denied the engagement in advance of publication."
People magazine said Aniston, who has starred in movies such as "Along Came Polly" and "Bruce Almighty," called to clarify the reports.
Aniston said she normally ignores rumors published about her but wanted to speak this time because the reports had been picked up by mainstream news outlets.
"The only reason I'm saying something is because if we're listening to the news we're supposed to be believing in the news," she said.
Aniston was vague about her relationship with Vaughn, 36, whom she met last year while filming "The Break-Up."
"We're just being," she told People. "We're having a good time."