The 50-year-old actress - who has three daughters Rumer, 24, Scout, 21, and Tallulah, 18 with her ex-husband Bruce Willis - was spotted dining in West Hollywood with Lindsay Lohan's ex-boyfriend Harry Morton, 31, despite recently insisting they are just friends.
A source told USMagazine.com: "She looked really very happy," as she enjoyed a romantic meal with the restaurant owner - who dated Lindsay in 2006 - in the back of the restaurant.
Demi reportedly looked flawless in a skin-tight dress and high heels, and seemed relaxed as she greeted other people in the club before leaving with Harry at around 10pm.
The dinner date is the latest of several outings for the rumoured new couple recently and it was previously revealed Demi is really enjoying getting to know Harry.
A source said: "They are just getting to know one another... (Demi is) in a really good place at the moment and is hopeful about the future."
Demi's new romance comes just weeks after she split from her toyboy lover Vito Schnabel.
The 26-year-old art dealer broke off their relationship last month after he became concerned that the attention surrounding their relationship would distract from his career.
Harry was also previously linked to Jennifer Aniston, whom he reportedly dated briefly in 2010.