The singer took to Twitter to share the happy news with fans.
He wrote: ‘Ayda and I are delighted to announce that Theodora Rose Williams is going to be a big sister. RW xxx.’
Robbie and Ayda welcomed their first child Theadora, or Teddy as the couple affectionately call her, in September 2012.
In an interview with Alan Carr last year, Robbie spoke about his life as a father and his desire to have another child.
‘My little girl is wonderful… Little Teddy. We are going to do more of them because they are amazing.’
‘She’s very kind and gentle,’ he added.
‘There’s nothing more heart-warming than having a child and I hate to use a Whitney Houston cliché but it really is the greatest love of all.’
Robbie met 34-year-old American actress Ayda Field whilst living in Los Angeles. She starred in soap operas and several American TV series before settling down with the 40-year-old former Take That singer.
The couple married in Beverly Hills in August 2010 after dating for nearly four years.
We can’t wait to meet Robbie’s new addition!