Stop what you're doing, everyone. Juventus are chasing a treble! The Old Lady have enjoyed a stellar campaign under Massimiliano Allegri, and look certain to take yet another Serie A title - they are nine points clear of Roma with just four games left to play and have won every single home game - and face Lazio in the Coppa Italia final at the end of May. They face French side Monaco in the Champions League semi-final this week - already being billed as the 'Unstoppable Force vs the Immovable...
Celtic - 1967
Once upon a time, Celtic were managed by a guy called Jock Stein and won the European Cup after beating Inter Milan in Portugal to earn themselves the nickname of the 'Lisbon Lions'.
They also secured a second of nine consecutive league titles and after that, toppled Aberdeen in the domestic cup final.
They also beat rivals Rangers in front of 100,000 people at Hampden Park in the League Cup final in October.
Ajax - 1972
Two words; Total. Football.
Rinus Michels is the man to thank for instilling that famous philosophy into the club, but it was Stefan Kovacs who delivered the club's treble in '72.
The Dutch club stormed to the Eredivisie title by winning 30 out of 34 games, and then beat Den Haag 3-2 to take the KNVB Cup.
They then went on to triumph in Europe by beating Inter Milan thanks to a brace from the late Johan Cruyff in De Kuip, the city of their great rivals Feyenoord.
PSV - 1988
PSV are another Dutch team to have won the treble, over a decade after the great Ajax team of the 70s.
Dutchman Guus Hiddink was in his first job as a manager and also in his first spell with PSV as boss in 1988 and, under his guidance, the team plundered 117 goals across all competitions.
Where the cups were concerned though, things weren't quite as straightforward - they required an extra-time goal from Soren Lerby to edge out Roda JC, and were taken to penalties in the European Cup final by Benfica.
Antonio Veloso missed the decisive spot-kick for the Portuguese side, after current Everton manager Ronald Koeman opened the scoring.
Manchester United - 1999
Perhaps the greatest Manchester United team there's ever been - certainly the fact that they won the treble would back that up.
United versus Bayern is widely considered one of the greatest Champions League comebacks of all time - not so much because of the scoreline, but because of the occasion and the nature of which the game was turned around in the blink of an eye.
Late goals from Teddy Sheringham and then Ole Gunnar Solskjaer sent United fans wild, and earned Sir Alex Ferguson a knighthood shortly after.
Before that, United had already claimed the league title on the final day of the season, and beat Newcastle in the FA Cup final, after the famous Ryan Giggs solo effort against Arsenal the round before.
Barcelona 2009 & 2015
Perhaps the greatest team of all time...
Pep Guardiola's debut season in 2008 actually got off to the worst possible start when he lost on the opening day of the season, but it turned out to be nothing more than a blip as Barcelona went on to dominate.
The Spanish giants played some absolutely scintillating stuff under the now-Manchester City boss that season. Notable results included a 6-2 demolition of fiercest rivals Real Madrid, and a 4-1 victory over Atletico Madrid to claim the Copa del Rey.
Not content with the double, Barca then outplayed Manchester United in Cardiff's Champions League final, and had people purring that they were watching the most aesthetically-pleasing team ever to play the game.
Barcelona made history at the end of the 2014/2015 season by becoming the first European club to claim a second treble in their history.
It was an incredible season that saw the attacking trio of Lionel Messi, Luis Suarez and Neymar plunder 122 goals between them in all competitions.
Barca claimed the league title by beating Atletico Madrid 1-0, their seventh in ten years, and beat Athletic Bilbao in the Copa del Rey final 3-1.
That was before they toppled Juventus in the Champions League final to stop them from winning a treble of their own. They are also the latest club to have enjoyed a treble winning season, including a trophy for Europe's most prestigious club competition.
Inter Milan - 2010
Not content with seeing his nemesis Pep Guardiola get all the attention in 2009, Jose Mourinho pulled off an incredible feat one year later with Italian side Inter Milan, when he won Serie A, the Coppa Italia and the Champions League.
Inter beat Roma 1-0 in the Coppa Italia and then ousted them in the league by just two points to secure an 18th title, before beating Bayern Munich in the Champions League final thanks to a Diego Milito brace, one game after a true Mourinho masterclass against Barcelona in the semi-final.
Bayern Munich - 2013
Everybody stood up and took note of Bayern Munich in 2012/2013.
Jupp Heynckes' final season saw him guide his team to an incredible treble as power started to shift away from Barcelona.
The Bavarians won the Bundesliga, the DFB-Pokal after beating Stuttgart 3-2, and the Champions League which saw them edge out league rivals Borussia Dortmund, after crushing Barcelona en route to the final, which got people particularly excited given the Catalans' reputation as the supposed 'best team in the world'.
They became the first German team ever to win a treble and allowed Heynckes to go out in style.