Delevingne, 22, and O'Connell, 24, have been together for a month, reported E! Online.
"They're having fun," a source said. Delevingne has not commented on the dating rumour, but she seemingly hinted at the relationship with a recent photo on Instagram. The photo she uploaded on Friday, shows a man's neck, presumably O'Connell's, featuring two "love bites." She captioned it with "Love bites #fittybum," and added heart emoticon.