Here, Press Association Sport looks at some of the best quotes from his time as Manchester United manager.
:: P IS FOR PHILOSOPHY (July 17, 2014)
During his unveiling press conference at Old Trafford, Van Gaal set his sights high and spoke of his philosophy for the first time.
"First I have to see how quickly the players can pick up my philosophy
I haven't worked with most of them and it is very important that there is a click between the players and the manager
For me, the challenge is always first and not fourth.''
:: LOATHING IN LA (July 23, 2014)
Annoyed at spending one hour meandering through traffic to get to the Pasadena Rose Bowl, Van Gaal uses his first tour press conference to launch an attack on the people who organised it.
When asked whether United's commercial commitments were impinging on football matters, Van Gaal said: ''More or less, yes because we have to prepare the season and when you have a lot of commercial activities also for the players, and you have to travel distances, you have to fly a lot, you have also jet lag, and that is not very positive for a good preparation
But the tour was already arranged so I have to adapt, I shall adapt.''
:: SHAW NOT FITTING IN (July 29, 2014)
Van Gaal criticises Luke Shaw for turning up to pre-season unfit following his £28million move to United.
"I think he [Shaw] needs to be fit and he is not very fit, therefore he can't perform what I want
He has to be fit first and to train individually."
:: IRON MAN LOUIS (October 25, 2014)
After Jose Mourinho attempted to play mind games with Van Gaal before Chelsea played United.
"I'm made from a little bit of iron," Van Gaal told reporters
"So I have a shield, an iron shield
Everybody can write or speak about me and I cannot change that."
:: FESTIVE GREETINGS (December 23, 2014)
Van Gaal raises a glass to the assembled press pack at his press conference last year.
"I am allowed to toast with you, my friends of the media
Merry Christmas
I wish your family a lot of love, health and happiness
Cheers
Not a bad wine
(It is) our sponsor."
:: LOUIS GETS TWITCHY (January 22, 2015)
When asked about supporters' criticism of his 3-5-2 system, Van Gaal said: "We have won more games with 4-4-2, but when you analyse the games we have twitched our ass
I said to my players I was squeezing my ass, but it was the wrong expression
I have twitched my ass on the bench because we were out of balance."
:: SAM GETS THE BOOT (February 11, 2015)
Annoyed at Sam Allardyce's claim that United played long-ball football against West Ham, Van Gaal hits back at the Hammers boss by producing a pamphlet of diagrams and charts which apparently undermine his opposite number's theory.
"When you have 60 per cent ball possession you cannot play long balls
So again, they did it 71 (per cent) and we 49, and I give it to you, you can copy it and then maybe you can go to Big Sam and he will get a good interpretation."
THE NIGHT OF THE SAXOPHONIST (May 20, 215)
After giving an eight-minute speech on stage, Van Gaal expresses his disappointment that a saxophonist at the club's end of year bash has not been given enough praise.
"We have the best fans in the world and I thank you for that..
but tonight I have seen a lady that plays the saxophone fantastically
Give her a big round of applause!"
VALDES HUMILIATED (July 15, 2015)
The first press conference of Van Gaal's second pre-season tour in Seattle proved to be just as exciting as the one he gave on his maiden tour
The Dutchman ditched goalkeeper Victor Valdes, a man he had known for 13 years, after he apparently refused to play for the reserves.
''Last season, he refused to play in the second team and there are other aspects you need as a keeper at United
When you are not willing to follow those principles, there is only one way and that is out.''
MISTAKEN IDENTITY FOR 'MIKE' (July 22, 2015)
After the tour had moved on to San Jose, Van Gaal spoke about the pecking order at Manchester United, but forgot the name of the third-most important player in the squad, who was sat next to him at the time.
"The players have to accept the captains
The first captain is Wayne Rooney, the second captain is Michael Carrick and the third is Mr Mike Smalling
I mean Chris, sorry."
LOUIS VAN GAAL'S ARMY (September 11, 2015)
Van Gaal responds to claims he has lost the support of the dressing room and the fans at United.
"The fans are shouting every week: Louis van Gaal's army! Louis van Gaal's Army! So also the fans are very satisfied with Louis van Gaal and the players are satisfied with me."
WE ARE ATTACKING! (December 5, 2015)
Annoyed at fans chanting "Attack, attack, attack" during United's 0-0 draw against West Ham, Van Gaal hits back in typically blunt fashion.
"I don't understand that they are shouting attack, attack, attack because we are the attacking team and not West Ham United."
"ENJOY THE WINE AND A MINCE PIE" (December 23, 2015)
Van Gaal walks out of his press conference after answering just three questions and says as he walks past a table of mince pies and wine laid on for the media: "Enjoy the wine and a mince pie
Goodbye."
BORING, BORING UNITED (January 11, 2016)
United were taking flack for a series of turgid performances and lack of attacking flair and Van Gaal admitted even he had found some of their displays rather dull.
"'There are matches that I have enjoyed and there are also matches where I'm very bored or angry because we are not disorganising our opponent's defence, but that is football."
GIVE ME HORNY FOOTBALL (February 24, 2016)
Van Gaal reveals the unusual style of possession he wants his players to adopt
"We have to keep the ball better and we have to move the ball quicker - that's always what we have to do
Desire is a great word
I often use the word 'horny' with my players."
SORRY I DIDN'T JOIN YOU SPURS (April 10, 2016)
Apologising for not taking over as Tottenham manager and branding Spurs a smaller club was perhaps not the wisest move given United had just been thumped 3-0 at White Hart Lane to slip 12 points behind their opponents.
''I like also to sign for Tottenham Hotspur
Daniel Levy knows that
But the challenge was bigger at Manchester United and shall always be bigger
I am sorry for Tottenham but Manchester United will always be the bigger club."
PARTING SHOT (May 21, 2016)
His team had just lifted the FA Cup after beating Crystal Palace but the post-match press conference was overshadowed by reports United had made the decision to replace Van Gaal with Jose Mourinho
Van Gaal remained defiant until the end.
''I show you the cup and I don't discuss it (my future) with my friends of the media, who already sacked me for six months
Which manager can do what I have done?''
Source : PA
Source: PA