Born in Unley, South Australia, Chappell was the second of three sons born in Adelaide to Arthur Martin and Jeanne Ellen (née Richardson), a Cornish Australian family. He was steeped in the game from a very early age: his father Martin was a noted grade cricketer in Adelaide who put a bat in his hands as soon as he could walk, while his maternal grandfather was the famous all-round sportsman Vic Richardson, who had captained Australia in Test cricket. Elder brother Ian and younger brother Trevor also played for Australia, and Greg closely followed in Ian's footsteps to the top. Given weekly lessons by coach Lynn Fuller, the brothers fought out fierce backyard cricket matches, with no holds barred. The fraternal relationship between Ian and Greg became legendary in Australian cricketing history for volatile verbal slanging matches, even during hard fought Test matches, which had their genesis in the family backyard.

Chappell attended St Leonards primary school, where he played his first competitive match at the age of eight; he also played a lot of baseball. Quite small for his age, Chappell developed a technique for dealing with the high bouncing ball by playing most of his shots to the leg side. Aged twelve, he hit his first centuries and was selected for the South Australian state schools team. He was then enrolled at Plympton high school for two years before following brother Ian and attending Prince Alfred College on a scholarship. Chappell recalled himself being an "economical" student whose mind often wandered to the cricket field during class. In the summer of 1964–65, Chappell suddenly grew ten centimetres in seven weeks and within twelve months had shot up to 189 cm. With this greater physical presence, Chappell was able to dominate schoolboy matches; in one of his matches for the school's First XI he scored a double ton and combined with classmate (and future Test teammate) Ashley Woodcock to put on more than 300 runs for the first wicket against Scotch College. Chappell's cricket coach at Prince Alfred, former first-class player Chester Bennett, described Chappell as "possibly the finest all-round schoolboy cricketer in my experience...he could go far in the game."

Early first-class career

The Chappell brothers played grade cricket for Glenelg and they batted together for the first time in a semi final against Port Adelaide in early 1966. Later that year, Ian was chosen for the Test tour to South Africa, which opened up a place in the South Australian team. Greg seized the opportunity by scoring 101*, 102* and 88 for his club, then made his first-class debut against Victoria at Adelaide Oval, aged 18. Hampered by a throat infection, Chappell still managed 53 and 62* to earn an extended trial in the team. The remainder of the season brought another 386 runs in 14 innings, including a maiden century against Queensland.

With the return of the Test players the following summer, Chappell held his place in the South Australian side and was promoted to the number four position, following brother Ian at number three. The highlight of Chappell's season was a brilliant 154 against Western Australia, but his con