The couple were rumoured to have split in January, but tried to revive their romance during their trip to Italy for the fourth season of Jersey Shore.
Ortiz-Magro was quizzed about his and Giancola's relationship while attending a Paranormal Activity 3 screening in New York City on Tuesday.
"We are not together," Ortiz-Magro told Us Weekly.
The pair first began dating while filming the first season of Jersey Shore in Seaside Heights in 2009.
Jersey Shore's Jenni 'JWoww' Farley recently insisted that she'd never date Ortiz-Magro because a romance eventually could damage their friendship.
Ortiz-Magro has said that he loves starring in Jersey Shore, even joking that he'll stay on the series until he's 70.
Jersey Shore airs Thursdays at 10pm ET on MTV.
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Watch Ronnie Ortiz-Magro and Sammi Giancola's recent Jimmy Kimmel Live interview below: