Published Saturday, 17 May 2014
The actress/TV presenter is set to become a first time mother with her ex-fiance, computer software tycoon Daniel Riley, who she separated from at the end of 2013.
Her news comes as the play she co-wrote, Sex and The Suburbs, opened in Liverpool on Friday.
Her agent said: "Claire could not be happier. To be pregnant and starring in her own show in her home town of Liverpool is all her dreams come true at once."
The actress confirmed the news on Twitter, writing: "Thrilled to say my show that I co wrote Sex and The Suburbs has opened to rave reviews, but the BEST news is I'm 5 months pregnant!!"
Sweeney became engaged to Riley in 2012 and they reportedly split after Christmas in 2013, although the news was only confirmed in April.