Having made a substitute appearance for Garry Rogers Motorsport at the final event of 2012, McLaughlin was signed by the team to compete full-time in the 2013 season.

The following season, McLaughlin took his maiden championship title after a close battle with Whincup's teammate Shane van Gisbergen in the second half of the year.

In 2019, McLaughlin dominantly won his second championship, winning a record 18 races during the season, including the Bathurst 1000, and securing the title with one event remaining.

[4] After his family relocated to the Gold Coast in 2003, McLaughlin began contesting Australian titles while also continuing to compete in New Zealand.

[5] In 2008, McLaughlin represented New Zealand in the Junior class at the Rotax Max Challenge Grand Finals, alongside Nick Cassidy.

[7] McLaughlin was part of the Britek Motorsport scholarship in 2008, which saw him working closely with team owner and Supercars race winner Jason Bright.

[9] McLaughlin completed a week of work experience with Stone Brothers Racing (SBR) in 2009, after which he was offered a four-year apprenticeship with the team, starting in 2010.

McLaughlin impressed during the test, recording lap times just over one second slower than those of the SBR's full-time V8 Supercar drivers Alex Davison and Shane van Gisbergen.

He was hit by Owen Kelly and Ryan Hansford, with the car suffering severe damage and taking McLaughlin out of the rest of the event.

McLaughlin suffered a heavy crash at Mount Panorama, hitting the wall at the Reid Park section of the circuit during the first race of the weekend.

[16] McLaughlin remained with SBR in 2011 and scored his first podium in the opening round at Adelaide, finishing seventh and second in the two races to be classified third overall.

[21] McLaughlin prevailed in a close title fight with Chaz Mostert, Scott Pye and Nick Percat; the quartet became known as the Dunlop Series' "Class of 2012",[22][23][24] with all four drivers going on to become race winners in the Supercars Championship.

McLaughlin also drove at the Sydney 500 for Garry Rogers Motorsport after Alexandre Prémat was forced out of the Sunday race due to extreme heat exhaustion the day before.

After starting strongly in the final round at Newcastle, a chaotic second race saw McLaughlin pick up three penalties which would eventually contribute toward him narrowly missing out on the title to Jamie Whincup.

McLaughlin finished third at Bathurst alongside Alexandre Prémat in which was the Ford Falcon's final appearance at Mount Panorama.

On 4 November, at Pukekohe Park Raceway, McLaughlin won race twenty-nine to join compatriot Shane van Gisbergen in winning the Jason Richards Memorial Trophy.

On 17 September, Team Penske announced that McLaughlin will instead make his IndyCar debut at the Firestone Grand Prix of St. Petersburg on 25 October.

[40] The day before the race he posted on his personal Instagram feed that he signed a multi-year contract with Penske to compete full time in the series.

[42] For the 2021 Indianapolis 500 he drove a Pennzoil-sponsored car, with the livery paying homage to that company's famed "Yellow Submarine" designs of the 1980s.

[43] Going into his rookie IndyCar season both Tim Cindric and Roger Penske let McLaughlin know that he was not expected to compete for wins and that his primary goal would be to finish all the races.

In his first race ever on an oval McLaughlin started fifteenth due to qualifying being cancelled by inclement weather, forcing the drivers to line up based on their championship points standings.

Not only did McLaughlin finish ahead of Tony Kanaan and Pietro Fittipaldi (who filled in for Johnson and Grosjean respectively), he finished ahead of all his Penske teammates and all the active drivers who had won the Indianapolis 500 other than Dixon; Takuma Sato, Alexander Rossi, Ryan Hunter-Reay, Tony Kanaan, and teammates Will Power and Simon Pagenaud.

[54] During the race McLaughlin ran for large portions at the back of the top ten before incurring a drive-through penalty on lap 116 for speeding in the pit lane, leading to a twentieth place finish.

[59][60] This meant that Grosjean had a chance at winning the IndyCar Rookie of the Year award despite not running a full schedule and McLaughlin racing in the double points earning Indianapolis 500.

[61][62][63] He picked up additional podium finishes at Texas, the second race at Iowa, Nashville, and Gateway, along with earning three pole positions on the season.

McLaughin would go into the season finale at Laguna Seca as one of five drivers contending for the Astor Cup, despite crashing out of the Indianapolis 500 and missing out on double points.

He started the year finishing third in St. Petersburg, but was stripped of his result after it was found out that Team Penske had illegally manipulated ECU software during the race to allow their drivers to use push to pass on restarts, which McLaughlin took advantage of.

The two met by chance in 2016 in Las Vegas when McLaughlin made the trip to help a fellow racer competing in an international karting tournament.

[71] After McLaughlin moved from Supercars to the IndyCar Series he and Karly relocated to North Carolina to be closer to Team Penske's headquarters.