A source told E! News that the 20-year-old singer and 21-year-old beauty queen Olivia were spied together at Ovest Pizzoteca in New York City on Thursday night (August 1).
The source revealed: "Nick was leaning in towards her across the table like she was saying something really important."
After their meal, the duo headed off down the street hand in hand, with the source adding: "They looked really happy when they walked together. Me and my friend both agreed they were, like, swinging their arms all happily."
Nick and Olivia met when he co-hosted the 2013 Miss USA pageant. Olivia is a former Miss USA who was crowned Miss Universe in 2012.
E! News writes that neither Jonas nor Culpo's reps were available to comment on the dating rumours.