The pop singer announced her happy news via an Instagram post on Monday afternoon, revealing that she and her family were “very happy” to be expecting a new arrival.
She wrote: “I know lots of people have been guessing and Ben and I can now confirm that Aoife is going to have a baby brother or sister next year!!! We're all very happy.”
Una and Ben already have one child, two-year-old Aoife Belle, who was born in March 2012.
The baby news comes just a day after Una's band, The Saturdays, kicked off their Greatest Hits tour in Glasgow on Sunday night, whizzing through a collection of their most popular tunes for excited fans who had come out to watch them perform.
This is a busy time for the girl group - in addition to Una’s pregnancy news, it was recently confirmed that Frankie Bridge would be taking part in the upcoming series of ‘Strictly Come Dancing’, where she has been partnered with professional dancer Kevin Clifton.
Unfortunately, Una's announcement was somewhat overshadowed by a slightly more high-profile pregnancy, after the news came on Monday morning that Kate Middleton, the Duchess of Cambridge, was expecting a child for the second time.