Rebecca Gibney led the outpouring of messages, saying a simple: ‘Rest in peace Connie.
'And thank you for sharing your journey with us all.'
The star also shared a black and white picture of the late mother of two.
Sarah Harris broke down in tears after hearing the much-loved mum had lost her battle.
The journalist was reduced to tears whilst appearing on The Project yesterday
Your heart breaks for those two little boys,' she said, whilst wiping away her tears.
Channel Seven personality Melissa Doyle also sent her well-wishes to the family.
'Rest in peace, brave beautiful soul #ConnieJohnson,' she said.
'The world is better for having had you in it.'
Radio stars Jonesy and Amanda also paid their respects, saying: 'Our hearts go out to you @samueljjohnson78 the fight doesn't stop here,' they wrote.
'Much love to you and the family at this time #loveyoursister.'
On Friday evening, Sam took to their Love Your Sister Facebook page to reveal the sad news.
'We lost Connie today. Or, as she asked me to say, she died of cancer today. It was so beautiful,' he wrote.
Continuing on, the 39-year-old said they had spent the day singing, reading messages of love and that she went 'so richly, and with such grace.'
Connie fought a long and very public battle with the disease - she was first diagnosed aged 11 - and she often had her brother by her side as he fought to raise funding for cancer research.
She was also a mother of two young boys, and was only yesterday awarded a Medal of the Order of Australia for her amazing work with her Love Your Sister charity.