The 70-year-old's death was confirmed by his Australian music publishing and recording house Alberts in an online statement from CEO David Albert on Monday.
"It is with great sadness that Alberts acknowledge the passing of George Young," the statement read.
"A consummate songwriter, trailblazing producer, artist, mentor and extraordinary musician, George was above all else a gentleman who was unfailingly modest, charming, intelligent and loyal, a man with a wonderful sense of humour.
"George was a pioneer who, with close friends Harry Vanda and Ted Albert, created a new sound for the Australian music industry. He will be missed."
Young rose to fame as a member of The Easybeats, playing rhythm guitar and writing hit singles including Friday On My Mind and Love Is In Air, the latter also made famous by John Paul Young.
His younger brothers Malcolm and Angus achieved fame in rock band AC/DC, with Young and The Easybeats' lead guitarist Harry Vanda co-producing the band's early albums including Let There Be Rock, Dirty Deeds Done Dirt Cheap, T.N.T, Powerage and High Voltage.
In a statement on its website, AC/DC said the band would not have existed without Young's help and guidance.
"As a musician, songwriter, producer, advisor and much, much more, you could not ask for a more dedicated and professional man," the statement read.
"As a brother, you could not ask for a finer brother. For all he did and gave to us throughout his life, we will always remember him with gratitude and hold him close to our hearts."
Young and Vanda embraced The Easybeats' 1969 split to produce many more bands under the 'Vanda and Young' title.
Over the years they produced albums by notable Australian acts The Angels, Rose Tattoo, Ted Mulry Band and Meatloaf.
Australian rock's stars took to social media to post their condolences, including Cold Chisel frontman Jimmy Barnes who described Young's passing as a "huge loss".
The Hoodoo Gurus' Dave Faulkner tweeted praise for Young's songwriting, posting a link to footage of The Easybeats live in Germany in 1967.
Vanda and Young were one of the first groups to be inducted the Australian Record Industry Association (ARIA) hall of fame in 1988, with Australian Musician magazine declaring in 1997 that the meeting of the duo at a Sydney migrant hostel in 1964 as the most significant event in Australian pop and rock music history.
They achieved success as a duo in front of the microphones, most notably as Flash and the Pan from 1977 to 1992.
They achieved success in Australia, while in European they notched four hit singles from 1983 to 1987 including Midnight Man and Ayla.
Young was again inducted into the ARIA hall of fame in 2005 as part of The Easybeats.
Following his friend's death, Harry Vanda issued a heartbreaking six word statement:
"Dear George, Rest in Peace my dear friend. Harry Vanda".
