Actress Olivia Wilde has revealed she is expecting a baby girl as she voiced support for US presidential hopeful Hillary Clinton.

The Hollywood star, who is engaged to actor Jason Sudeikis, announced she was pregnant with her second child earlier this year.

Olivia Wilde has announced she is expecting her second child
Olivia Wilde ( Jordan Strauss/Invision/AP)

In a post on Twitter, Olivia revealed she will be welcoming a daughter as she retweeted a campaign video for Mrs Clinton.

The video features clips of Republican candidate Donald Trump using derogatory remarks towards women and ends with the question: “Is this the president we want for our daughters?”

Olivia wrote: “As someone who is about to have a daughter, this hits me deep in my core. #NeverTrump.”

The actress announced she was pregnant in April by posting a touching photograph on Instagram as she sat in bed with her young son Otis.

As Olivia held her baby bump, two-year-old Otis copied his mother by cradling his own stomach. The picture caption reads: “Matching baby bumps.”

Olivia is well known for her role as Dr Remy “Thirteen” Hadley in television series House, starring Huge Laurie, as well as appearances in films Tron: Legacy, Cowboys & Aliens, Her and Rush.

Olivia Wilde and Jason Sudeikis
Olivia Wilde and Jason Sudeikis (Clint Spaulding/AP)

She and former Saturday Night Live star Jason got engaged in 2013. She was previously married to Italian film-maker Tao Ruspoli.