Dunham: We wanted Dornan on Girls
But the 27-year-old, who created, writes, directs and stars as aspiring writer Hannah Horvath in the comedy-drama, admitted that it is unlikely to happen as they approached him after he was cast in the Fifty Shades Of Grey film.
"We requested Jamie Dornan but the thing is, we requested him post Fifty Shades Of Grey casting (and) it was already gone," she said at a launch for the show's third series.
"It was too late. He's amazing, I just don't think we can have him," she added.
Jamie is set to star in Sam Taylor-Johnson's big-screen adaptation of EL James' raunchy novel as kinky billionaire Christian Grey opposite Dakota Johnson as love interest Anastasia Steele. The film has started shooting in Canada, for a planned release in 2015.
Lena let slip that her co-star Allison Williams, who plays her screen best friend Marnie Michaels, would like Zac Efron to guest star.
"Allison wants Zac Efron. There's so many actors and we try to write with actors in mind so they really are perfectly suited," she said.
He joked that acquaintances would approach him for a role, saying: "When I was in New York, almost every single actor I knew came up to me and said, 'Can you get me in there because I want to have a part?' I'm sorry, I can't. Everyone wants to be in it."
The third series of Girls, which also stars Zosia Mamet, Adam Driver and Jemima Kirke, premieres on Sky Atlantic on January 20.