The couple's happy news was announced on the official Take That Twitter page with the message:
"Mark, Emma, Elwood and Willow are delighted to announce the arrival to the clan of their beautiful new baby girl Fox India Owen.
"She was born yesterday at 7.45am weighing 7lb 1oz. They would like to thank all their friends and family for all the wonderful messages xxx."
Mark and Emma already have two children, son Elwood, six, and daughter Willow, four.
Mark's bandmates Gary and Robbie are also set to be dads this year. Gary's wife Dawn is expecting the couple's fourth baby, while Robbie and wife Ayda are due to welcome their first child later this year.
Congrats Mark and Emma! Not quite convinced on the name choice though....
Do you think there's a woodland them going on there - Elwood, Willow, Fox?