The former Spice Girls singer - who is engaged to singer-turned-chef Jade Jones, with whom she has three-year-old son Beau - revealed on twitter she has named her new baby Tate, though she did not reveal the exact date of his arrival.
Writing on twitter, she said: "Our beautiful son Tate has arrived safe and sound! We are all so happy and excited. Thanks and love to you all. Xx(sic)"
Emma recently revealed she and the other Spice Girls - Mel B, Mel C, Victoria Beckham and Geri Halliwell - have been bonded together by the shared experience of motherhood.
She said: "Because we`re all so busy we don`t get to see as much of each other as we`d like but when something like this happens the bond we have shines through. It`s like a sisterly relationship and that will always be there.
"In fact Scarlet [Mel C`s daughter] and Cruz [Victoria and David Beckham`s son] have birthdays in a few days so it`s great excuse to get together."