Ingall was born in England and moved to Port Adelaide in South Australia with his father at the age of three. His father was a motor mechanic who operated a service station; his mother died from breast cancer when Ingall was young. He began karting at twelve on the Whyalla go-kart track, and after winning Australian junior and senior karting championships he moved to Europe to compete. During his karting career he lost the top joint of his right index finger in an accident, an injury that did not deter his progress.
Ingall entered Formula Ford in Europe, finishing runner-up in the Motorcraft Formula Ford Driver to Europe Series before winning it outright in 1990. He made his Bathurst 1000 debut that same year co-driving a Holden Commodore VL for Bob Forbes Racing with Kevin Bartlett.
He headed to Britain in 1991, nearly winning the British Formula Ford Championship and competing in the GM-Lotus formula before moving to Germany for the Formula Three Championship with Team Schübel. A Macau Grand Prix appearance saw him start 23rd, overtake David Coulthard, and finish fifth. In the New Zealand Formula Ford series over the following northern winter he won ten of twelve races.
His most emphatic European achievement came in 1993, when he won 13 of 16 races in the British Formula Ford Championship for the factory Van Diemen team — a record for victories in a single season in the championship's history — and capped the year by winning the Formula Ford Festival and World Cup at Brands Hatch.
After time in the Japanese Formula 3 Championship in 1994, Ingall returned to Australian touring cars, driving for Wayne Gardner Racing at the Sandown 500 and Bathurst 1000, where he and Win Percy led for a period before finishing fifth.
He won the 1995 British Formula Renault Championship before joining Perkins Engineering for the Australian endurance races that year, featuring prominently in the team's dramatic last-to-first victory at Bathurst. He became a full-time competitor from 1996 and won his first championship round at Calder Park that season. The 1997 Bathurst 1000 brought his second Bathurst victory. Over seven seasons at Perkins, Ingall was championship runner-up three times — in 1998, 1999 and 2001 — and finished third in 1997, building a reputation as one of the most consistently competitive drivers in the field without yet claiming the title.
Ingall joined Stone Brothers Racing in 2003 and began the season with wins in the support races at the Australian Grand Prix. He finished seventh in the championship. In 2004 he was again a consistent frontrunner, winning a round at Symmons Plains and finishing second in the championship — matching Stone Brothers Racing teammate Marcos Ambrose's title win with a team 1-2 at the final round.
In 2005 Ingall delivered the championship he had long threatened, taking the V8 Supercars title ahead of Craig Lowndes and Marcos Ambrose. His approach that season was notably calculated: he worked through the points system strategically race by race, running smarter than he had before rather than relying purely on outright pace. The title came at the season finale at Phillip Island.
His 2006 season was disappointing — he slipped to eighth in the standings despite the car's shortcomings — and a poor 2007 saw him finish outside the top ten in the championship for the first time in his career.
In 2008 Ingall moved to Paul Morris Motorsport — now sponsored by automotive retailer Supercheap Auto — and continued racing with that team through 2011. He moved to Walkinshaw Racing in 2012 and stayed through 2013, the year he became the all-time record holder for Supercars Championship race starts, surpassing John Bowe's mark of 225 at Townsville. He retired from full-time competition at the end of 2014.
Ingall continued to compete in endurance events after his full-time retirement. He drove for the Holden Racing Team at the 2015 Sandown 500 and Bathurst 1000 when James Courtney was injured. He joined Nissan Motorsport for the 2016 Pirtek Enduro Cup alongside Rick Kelly, and returned to the Bathurst 1000 in a Triple Eight Race Engineering wildcard in 2021, sharing the car with Broc Feeney.
Ingall joined Fox Sports after his retirement as a co-host on the network's V8 Supercars coverage alongside five-time champion Mark Skaife. He also hosts an online video series titled Enforcer and The Dude alongside former rival and team owner Paul Morris.