Joshua Daniel "Josh" Hartnett (born July 21, 1978) is an American actor and movie producer. He first came to attention in 1997 for his role as Michael Fitzgerald in the television crime drama series Cracker. He made his feature film debut in 1998 in the slasher film Halloween H20: 20 Years Later, followed by teen roles in films such as the sci-fi horror film The Faculty (1998) and the drama The Virgin Suicides (1999). Hartnett had starring roles in the war film Pearl Harbor, the drama O, the war film Black Hawk Down, the romantic comedy 40 Days and 40 Nights, the crime thriller Lucky Number Slevin (2006), and other films.

He starred in the Brian De Palma–directed neo-noir crime thriller The Black Dahlia (2006). Next, he appeared in the drama Resurrecting the Champ (2007), alongside Samuel L. Jackson, the graphic novel–based vampire horror film 30 Days of Night (2007) and the neo-noir atmospheric thriller I Come with the Rain (2009). From 2014 to 2016, he starred as Ethan Chandler in the horror TV series Penny Dreadful, for which he was nominated for a Fangoria Chainsaw Award.