Ashlee Simpson made her red carpet debut with "Boardwalk Empire" star Vincent Piazza on September 14 at an event for the show's season premiere.
Simpson, a 26-year-old actress and singer and Piazza, who plays Lucky Luciano on the HBO series, were also spotted at various fashion shows during New York Fashion Week.
The two sparked relationship rumors in June, when Simpson was photographed with her arm around the actor and were said to be spotted kissing. Simpson split from her husband Pete Wentz earlier this year.
In February, Simpson filed for divorce from Wentz, a 32-year-old member of the rock band Fall Out Boy and the father of 2-year-old son Bronx, their only child. They married in May 2008.
"Ashlee's been my best friend for five years; she's the mother of my child," Wentz said on Ryan Seacrest's KIIS FM radio show in March. "I have nothing but love and respect for her and going through something like this isn't easy, but we're friends and the most important thing is to put our son first."