While recovering from a ruptured anterior cruciate ligament, Evans contested the 245 km men's road race at the Beijing Olympics, finishing 15th, 22 seconds behind Samuel Sánchez. He placed fifth in the road time trial four days later.

Cadel Evans was born on 14 February 1977 at the Katherine Hospital, Katherine, Northern Territory, Australia, to Helen (née Cocks), a bank manager, and Paul Evans, a council foreman. He spent his early childhood in the small Aboriginal community of Barunga, 80 km east of Katherine. At the age of seven, he was hit in the head by a horse, and spent seven days in an induced coma. In 1986, his parents separated and he first moved with his mother to Armidale, New South Wales, and then to the Melbourne suburb of Eltham, Victoria, where his mother still lives. Evans attended Newling Public School in Armidale, and Eltham High School in Melbourne. Skateboarding was one of his teenage interests. His father describes him as a good student, but otherwise just an ordinary kid who would leave his toys around; "Not in [my] wildest dreams" would he imagine that his son would become a top world athlete.

Evans' win elicited much celebration in his home nation with calls for a national holiday as his win was compared to that of the 1983 America's Cup which was considered Australia's greatest sporting achievement. Australian Prime Minister Julia Gillard phoned to congratulate Evans saying that "I do want to say a very big congratulations to Cadel Evans. I had the opportunity this morning to speak and to personally offer my congratulations. I believe I disturbed him while he was trying to get a nice, hot bath."

Evans won bronze medals at the 1995 Junior world mountain bike championship and Junior world road time trial championship, and silver medals at the 1997 and 1999 under-23 world championships. He won the cross-country event in the Mountain Bike World Cup in both 1998 and 1999. In 1998 Shayne Bannan was the under-23 road cycling coach based in Italy.

In 1997, he rode for the Diamondback MTB team, and then for the Volvo-Cannondale MTB team.

Cadel Evans had a breakthrough road cycling performance at the 1999 Tour of Tasmania, where commentator Phil Liggett famously proclaimed that Evans would win the Tour de France one day. It wasn't until 2001, however, that Evans officially made the switch to road cycling and joined the Saeco team.

Other early successes included overall wins in the 2001 and 2004 editions of the Tour of Austria, 14th in the 2002 Giro d'Italia (he wore the general classification leader's pink jersey for one day), Commonwealth Games time trial champion in 2002, a stage win of the 2002 Tour Down Under, fifth in the 2005 Deutschland Tour, and winning the mountains classification in the 2006 Tour Down Under.

In this year, Evans joined an elite group of cyclists who have all worn all three Leaders jerseys; the pink jersey for the leader of the general classification in the Giro d'Italia in 2002, the yellow jersey for the leader of the general classification in the Tour de France for 4 days in the 2008 Tour de France, and the gold jersey for the leader of the general classification in the Vuelta a España in 2009. He was awarded Australian Cyclist of the Year for the third time.

In 2005, Evans married Chiara Passerini, an Italian Pianist and music Teacher he met at the end of 2002. Evans proposed to her after his first Tour de France. In January 2012, the couple adopted their son Robel, from Ethiopia, at the age of six months. Evans and Passerini separated in 2015.

Winning The Sydney Morning Herald 2007 Sports Performer of the Year, Evans pledged to donate his $50,000 winner's prize to charity, including the Amy Gillett Foundation, established in memory of Australian rower and Cyclist Amy Gillett, who was killed on the eve of a stage race in Germany in 2005, when she and her Australian teammates were struck by a car. Another nominated beneficiary was Ian Thorpe's Fountain for Youth, established by the Olympic Swimmer to alleviate and treat illness and disease in people under 20. Making the announcement, Evans revealed that Thorpe had visited the Northern Territory Aboriginal community of Barunga where Evans lived until the age of three.

In 2008, Evans wore a cycling undershirt with the Flag of Tibet and supported freedom for Tibet. He said:

A biography, Cadel Evans: Close To Flying, was published by Hardie Grant Books in November 2009.

In support of youth mental health initiatives of Orygen Youth Health, Evans has featured in the annual Suit Up & Ride corporate team cycling event in Melbourne since 2010.

Evans had a much more successful start to 2011, winning stage 4 and the general classification at the Tirreno–Adriatico, and the general classification at the Tour de Romandie, both of which form part of the 2011 UCI World Tour. Skipping the Giro d'Italia, Evans prepared for the 2011 Tour de France by finishing as runner-up in the Criterium du Dauphine, one of the major Tour warm up events.

Evans' first cousin is Australian London 2012 Paralympian Matthew Haanappel.

Evans was made a Member (AM) in the General Division of the Order of Australia on 10 June 2013.

Evans participated in the inaugural Cadel Evans Great Ocean Road Race in February 2015, finishing fifth. Evans announced his retirement after the race. Cadel Evans is now the Global Ambassador for the BMC Racing team.

In March, 2017, Evans was back on a mountain bike and competing in the Masters category at the eight-day Absa Cape Epic stage race in South Africa over 641 km. The race is held in a two-person team format and Evans and partner George Hincapie – his domestique at the 2011 Tour de France – won the category.