Cheika had a stint in charge of French club Stade Francais and went on to guide Australian side Waratahs to a Super Rugby title before moving to the international rugby stage as Wallabies boss.
He spent five years at the helm of the Australia side and after leaving in 2019 he took on an assistant coaching role with Argentina before becoming head coach in 2022.
While with Argentina, he also juggled being head coach of the Lebanon national rugby league side, who he guided to the knockout stage of the World Cup in 2022.
The Leicester Tigers job now sees him move back to club rugby for the first time in a decade.
He will be the eighth head coach to lead Tigers in less than eight years, with long-time boss Richard Cockerill leaving in January 2017 and followed by caretaker Aaron Mauger, then Matt O’Connor, Geordan Murphy, Steve Borthwick, Richard Wigglesworth and McKellar.
Borthwick guided Tigers to an 11th Premiership title in 2022 before leaving for the England job, and under Wigglesworth the club got to the play-offs in 2023.
McKellar’s solitary season at the helm ended with Tigers finishing eighth in the Premiership, being knocked out of the European Champions Cup in the second round and losing the Premiership Cup final.
Despite the disappointing campaign, his departure came as a shock as he completed his coaching team just a week earlier with the addition of Australian Peter Hewat as attack and backs coach.
The coaching set-up has now had to be rebuilt, with scrum coach Dan Palmer quitting on the eve of Cheika’s appointment.
Tigers chief executive Andrea Pinchen said Leicester consider Cheika to be the “right person to take this team, this club, back to where we know we should be”.
Pinchen added: “I also accept that the past week is not what fans expected, and nor did we, but the decisions we have made are for the long-term benefit of Leicester Tigers and after lengthy, detailed and very honest conversations with Michael in recent days, we are on the same page about what is now necessary to see this club back on top.”