Ronald Belford "Bon" Scott (9 July 1946 – 19 February 1980) was an Australian singer who was the second lead vocalist and lyricist of the hard rock band AC/DC from 1974 until his death in 1980. In the July 2004 issue of Classic Rock, Scott was ranked number one in a list of the "100 Greatest Frontmen of All Time". Hit Parader ranked Scott as fifth on their 2006 list of the 100 Greatest Heavy Metal Vocalists of all time.

Born in Forfar in Angus, Scotland, Scott spent his early years in Kirriemuir. He moved to Australia with his family in 1952 at the age of six, living in Melbourne for four years before settling in Fremantle, Western Australia, then Adelaide, South Australia in his later years. Scott formed his first band, the Spektors, in 1964 and became the band's drummer and occasional lead vocalist. He performed in several other bands, including the Valentines and Fraternity, before replacing original AC/DC lead singer Dave Evans in 1974.

With AC/DC Scott performed on the band's first seven albums: High Voltage (1975, Oceania only release), T.N.T. (1975, Oceania only release), High Voltage (1976, first international release), Dirty Deeds Done Dirt Cheap (1976, not released until 1981 in the United States), Let There Be Rock (1977), Powerage (1978) and Highway to Hell (1979). AC/DC's popularity grew throughout the 1970s, initially in Australia, and then internationally. Their 1979 album Highway to Hell reached the top 20 in the United States, and was their commercial breakthrough. However, on 19 February 1980, Scott died after a night out in London with former musician and alleged drug dealer Alistair Kinnear. AC/DC briefly considered disbanding, but the group recruited vocalist Brian Johnson of the British glam rock band Geordie. AC/DC's subsequent album, Back in Black, was released only five months later, and was a tribute to Scott. It is currently the second-best-selling album of all time.

Ronald Belford Scott was born on 9 July 1946 at Fyfe Jamieson Maternity Hospital in Forfar, Scotland, to Charles Belford "Chick" Scott (1917–1999) and Isabelle Cunningham "Isa" Mitchell (1917–2011). He grew up in Kirriemuir and was the Scotts' second child; their first was a boy born in 1943, Sandy, who died shortly after birth. A third child, Derek, was born in 1949. Chick and Isa ran the family bakery in Kirriemuir's Bank Street. The family emigrated from Scotland to Australia in 1952.

The Scotts lived in the Melbourne suburb of Sunshine, Victoria, and Scott attended the nearby Sunshine Primary School. He received the nickname "Bon" shortly after starting school; because there was another Ronald in the class, his classmates played on the phrase "Bonnie Scotland". A fourth child, Graeme, was born in 1953.

In 1956, the family moved to Fremantle, Western Australia. Scott joined the associated Fremantle Scots Pipe Band, learning the drums. He attended North Fremantle Primary School and later John Curtin Senior High School until he dropped out at the age of 15. He subsequently worked as a farmhand and a crayfisherman, and was later a trainee weighing-machine mechanic. In 1963 he spent a short time in Fremantle Prison's assessment centre and nine months at the Riverbank Juvenile Institution, relating to charges of giving a false name and address to the police, having escaped legal custody, having unlawful carnal knowledge, and stealing 12 imperial gallons (55 L) of petrol. He attempted to join the Australian Army, but was rejected and deemed "socially maladjusted".

Scott's vocals were inspired by his idol, Little Richard. After working as a postman, bartender and truck packer, Scott started his first band, the Spektors, in 1964 as drummer and occasional lead singer. In 1966, they merged with another local band, the Winstons, and formed the Valentines, in which Scott was co-lead singer with Vince Lovegrove. The Valentines recorded several songs written by George Young of the Easybeats. "Every Day I Have to Cry" (a song originally written and sung by Arthur Alexander) made the local record chart. In 1970, after gaining a place on the National Top 30 with their single "Juliette", The Valentines disbanded due to artistic differences after a much-publicised drug scandal.

Scott relocated to Adelaide in November 1970 after he joined the Sydney-formed progressive rock group Fraternity on lead vocals. They had local chart success with their version of Blackfeather's "Seasons of Change" (March 1971). Scott had previously played recorder on Blackfeather's version. Fraternity released the LPs Livestock and Flaming Galah before touring the UK in 1973, where they changed their name to Fang. During this time they played support slots for Status Quo and Geordie, whose front man Brian Johnson would eventually succeed Scott as the lead singer of AC/DC after his death. During this time, on 24 January 1972, Scott married Irene Thornton.