The singer is heartbroken for his Take That bandmate after his wife Dawn delivered their daughter Poppy Barlow stillborn on Saturday (04.08.12) and he wants his friend to know he is thinking of him.
In a blog post on his official website, he wrote: ''MY THOUGHTS ARE WITH GARY DAWN AND FAMILY RIGHT NOW X (sic)''
Robbie and his wife Ayda Field are expecting their first child together in the coming weeks.
Many of Gary's friends have sent him messages of support in this difficult time.
Louis Walsh - who is a judge on 'The X Factor' with the 41-year-old musician - wrote on his twitter page: ''#RIPPoppy Retweet for respect as Gary Barlow's daughter is born stillborn. Thoughts and prayers are with his family at this sad time. (sic)''
Frankie Cocozza - who Gary supported when he was kicked off the last series of the pop star search show for his wild off-screen antics - also took to twitter to offer his sympathies to the 'Patience' singer.
He wrote: ''My thoughts are with Gary Barlow and his family, such terrible news.''
Harry tweeted: ''My Love, thoughts and prayers are with @GBarlowOfficial and his family at such a difficult time. .xx (sic)
In a statement, Gary said: ''Dawn and I are devastated to announce that we've lost our baby. Poppy Barlow was delivered stillborn on August 4th in London.
''Our focus now is giving her a beautiful funeral and loving our three children with all our hearts. We'd ask at this painful time that our privacy be respected.''