The Californian squad, which has taken GT World Challenge America spoils in each of the last two seasons, will be back for the full GTWCE season for the first time since it managed a best finish of sixth running Bentleys in the COVID-impacted 2020 season.
It also entered last year's Spa 24 Hours with Orange1, placing 11th overall with American team regulars Andrea Caldarelli and Jordan Pepper joined by Marco Mapelli.
K-PAX will pair 22-year-old Mitchell, who has been on the books of the Italian supercar manufacturer since winning the British GT title in 2020, with fellow works aces Mapelli and Franck Perera.
It will be the Scot's first season in a full Pro car having previously raced in the Silver, Pro-Am and Gold Cup classes in GTWCE and has two class wins in the Spa 24 Hours to his name with Barwell Motorsport.
"I've raced in almost all the classes in GTWCE, so it's great to have a chance in a Pro car which is a huge thing for my career and an opportunity that I've been working hard to get," said Mitchell, who will also contest British GT with Barwell alongside Shaun Balfe.
"I know Marco and Franck and get on well with them, so I think we’ll work well together. All three of us are good team players, so that can be a strength of ours to try and get the best out of the car.
"We'll be looking to have good, consistent races, and GT World Challenge is all about taking the chances when they're there, because it's very rare that that one or two cars do well in all races, with it being so highly competitive, and especially in the top 10-15 places.
"The highlight of the year is going to be the Spa 24 Hours, which is a race I've won in two classes already with Pro-Am and Silver, so it would be pretty cool do that in Pro.
"K-PAX Racing always have really good speed and put on a really good showing last year in the Spa 24 Hours, so I've got no doubts that the car is going to be quick and we'll have a good team around us."
Team principal Darren Law said: "We have worked with both Marco and Franck previously, and raced against Sandy, so it will be great to have him joining our programme this year.
"We are looking forward to the challenge and can't wait to get the season started.”
Law explained that K-PAX had "unfinished business" in Europe after its first assault in 2020 and has leased a workshop in Italy as it gears up for the official GTWCE Paul Ricard test on 7-8 March before the opening round at Monza on 23 April.
"We will use part of our US team members and a partial crew from Europe," he said.
"All the equipment is in containers on its way and both our cars are at Lamborghini Squadra Corse now getting updated to the new EVO2 spec.
"Fingers crossed everything makes it in time for the first test at Paul Ricard but if not, we have support from Lamborghini if needed."
K-PAX is the first Lamborghini squad to announce its driver lineup for 2023. Iron Lynx is expected to run two Pro crews under its own name, having entered Lamborghini's traditional #19 and #63, in addition to an all-female lineup under the Iron Dames banner following its switch from Ferrari.
