Mushroom Group, the entertainment business Gudinski founded in 1972, confirmed he died in his sleep on Monday night at his Melbourne home aged 68.
Gudinski was a towering figure in Australian entertainment, with Mushroom expanding into touring, publishing, booking agencies and film and TV production.
Rock star Jimmy Barnes paid a heartfelt tribute to his close friend on Tuesday.
"Michael was the rock I reached for when life tried to wash me away," he said.
Barnes said Gudinski had stood by him "through my darkest moments and my most joyous days", and had always been there for anyone who needed him.
He said the Australian music business had changed and grown because of Gudinski.
"Today the heart of Australian music was ripped out," he said.
"His boundless enthusiasm breathed life into our music scene."
Frontier Touring, founded under the Mushroom umbrella in 1979, is one of the key concert promotion companies in Australia and New Zealand.
Gudinski also launched the music careers of fellow Melburnians Kylie and Dannii Minogue.
"A larger-than-life figure, Michael was widely respected for his unwavering passion for all music - in particular Australian music," a Mushroom statement said.
"Michael was renowned for his loyalty and dedication. His ability to achieve the unachievable against unsurmountable odds was proven time and again and spoke to his absolute passion for his career and life."
Oscar-winning actor Russell Crowe was among the first to post a tribute to Gudinski on social media.
"Seems almost impossible. A towering figure on the Australian cultural landscape," Crowe tweeted.
"I'm not sure we ever agreed on anything ... still didn't stop us from being mates for 30 years. I'm going to miss him deeply. My love to his family."
Federal Labor's arts spokesman Tony Burke said he counted Gudinski as a friend.
"I liked him a lot. I'll miss him a lot. The story of Australian music will always have Michael in a lead role. Half larrikin, half genius, he made sure our nation had its own soundtrack," Mr Burke said.
Most recently, Gudinski developed the Music From The Home Front TV concert to showcase the local music industry as it struggled through the coronavirus pandemic.
Gudinski is survived by his wife Sue, son Matt, daughter Kate and two grandchildren.
"Michael often referred to his 200+ staff as the Mushroom Family, with many having clocked decades in his employment," the company said.
