Over a career spanning half a decade, Willesee worked for Channel 7, Channel 9 and the ABC.
Channel 7's Melissa Doyle was one of the first to pay tribute to the talented journalist.
'Deeply saddened to hear that our colleague and TV legend Mike Willesee has passed away,' the TV host Tweeted.
'Our thoughts are with his family. We’ll remember an incredible journalist, tenacious and tough. A loss for our industry. #sn7 #7news'
Media personality Derryn Hinch also paid his respects.
"Shock, sad news. We clashed a lot but he was one of the TV current affairs trailblazers. The master of the destructive, disbelieving, pause in interviews," he Tweeted.