The Portuguese manager returns to Stamford Bridge six years after his first spell and more or less proved to be nothing but successful in his two spells since delivering two Premier League titles for the Europa League champions.
The competition was fierce and to win a title against what some people describe as the greatest club side of all time, greater reflections might be more flattering to Mourinho's spell at the Santiago Bernabeu.
After Roberto Di Matteo claimed the Champions League last year as interim manager, Roman Abramovich completed the set and finally landed the holy grail that he had coveted so highly for so long.
Upon that famous victory in Munich, ambitions were reassessed, and Chelsea needed to reevaluate their strategy moving forward, looking at a more sustainable plan that could ensure the club develop a way of returning to the pinnacle of European football time and again.
While Chelsea fans will be absolutely delighted with the appointment, there were plenty of other outstanding candidates who would have been better choices for the Blues.
While trophies are important, this appointment surely needs to provide more—defining a footballing philosophy and club identity that the supporters can be proud of, youth development and integration, not to mention an ability to work with lesser resources over time and maintain high standards on the pitch.
Here are three candidates who might have been a better choice for Abramovich.
Manchester City's next manager in all likelihood, Manuel Pelligrini oozes class and a certain charm in the way he carries out his work.
Considering the damage to the club's reputation over the years by Mourinho's brash persona in particular, the Chilean would have offered a smooth personality that would have appeased the neutral fan and made the team more likeable—something that might not be essential to Abramovich, but is certainly desirable.
Pellegrini might not have such a proven record of delivering trophies as Mourinho, but he has delivered league titles in Argentina with big clubs such as San Lorenzo and River Plate, proving his ability to adapt to enormous expectations, something not prevalent in his past two jobs in Spain.
His time at Villarreal and Malaga have demonstrated how he can deliver success without a heap of resources, which could become crucial down the line when UEFA's financial fair play rules kick in.
With two modest Spanish teams, Pellegrini also has an impressive Champions League record, reaching a semi-final and a quarter-final to exceed any expectations.
A year at Real Madrid without a trophy was rather forgettable, but by delivering a 75 percent win record, it shows that Pellegrini can deliver results when afforded the luxury of top class players and a deep squad.
Carlo Ancelotti is one manager that the Blues' fans never quite came to terms with after his sacking.
The Italian delivered a double in his first season, but was soon gone after failing to back that up in his second season, and his dismissal left many fans bemused.
Ancelotti is perfect for a club like Chelsea that removes total control over all footballing matters for its manager.
Technical director Michael Emenalo will have substantial authority, while the owner himself will have the overriding say on all matters, something that is not always the case.
Ancelotti has proved to be willing to accept such decisions in his time with Milan, Chelsea and now PSG. The 53-year-old continues to work without drama and offers a terrific tactical repertoire.
A more attractive style is also instilled by Ancelotti, which has always been something that Mourinho has been criticised for to an extent.
Succumbing to Montpellier in his first season in charge of Les Parisiens was a major blow and somewhat damaging to Ancelotti's reputation, so it remains to be seen whether he can still deliver domestically in a competitive league—Ancelotti famously struggled to deliver the scudetto regularly in his time with Milan, winning just once in eight years.
With the Champions League monkey off Chelsea's back, reestablishing themselves as the major force in the Premier League is paramount, and a win percentage of 63.16 during his time at Stamford Bridge in the EPL is below that of Mourinho.
Diego Simeone would have been a wild card for Chelsea, but a candidate who could have provided something different.
The job that he has done at Atletico Madrid has been marvellous, delivering the Spanish cup this season by defeating city rivals Real Madrid in the final.
The key to his success has been a rock-solid defence, something that Chelsea's most successful teams in recent season have been famed for.
Atletico are certainly not boring to watch though, and the balance that Simeone has found is very impressive.
With greater resources at his disposal, I feel that Simeone could reach the very top of European football and that Chelsea would have suited him perfectly.