The 'Young' singer was seen with the Skins actor for a third time in recent weeks, further increasing rumours that they have become an item.
The pair visited the Egyptian-themed restaurant Little Bay in Kilburn, North London, along with O'Connell's mother and sister, reports The Sun.
Jack O'Connell has denied that he and Contostavlos are romantically involved.
Contostavlos recently dismissed claims that she purposefully leaked a sex tape featuring herself and a former boyfriend in order to promote her debut single.
The X Factor judge is suing MC Ultra for up to £100,000 for the leaking of the video.
Watch the video for Tulisa's 'Young' below: