Published Thursday, 13 March 2014
Katherine Kelly stars as Lady Mae Loxley in Mr Selfridge. (© Getty)
The 33-year-old and husband Ryan Clark became parents to baby girl Orla on Tuesday.
She said she was "overwhelmed with joy to announce the arrival of our daughter".
Clark added: "Katherine has given me the best gift in the world. Absolutely smitten with Orla and so proud of my wife."
The couple married in a low-key ceremony at the Little Church Of The West in Las Vegas last year.
Kelly left Coronation Street in 2012 after six years playing Becky McDonald.
Her former co-star, Paula Lane, who plays Becky's sister Kylie, was one of the first to congratulate the actress, writing on her Twitter page: "Amazing news katherine kelly and Ryan. A beautiful baby girl xxx."
© UTV News