The club announced on Monday that the vastly experienced Dutchman will take charge at Old Trafford when his commitments as Holland boss end following this summer's World Cup.
His arrival could therefore come approximately 12 months after David Moyes formally began work as Sir Alex Ferguson's successor on July 1 last year.
United will hope for a much different outcome this time and Van Gaal has already made his first popular decision by installing club hero Ryan Giggs as his assistant.
Giggs, 40, has ended his illustrious playing career, after a record 963 appearances and 13 Premier League titles with United, to take up the post as Van Gaal's number two.
That combination could lift spirits after Moyes' ill-fated regime, which ended with the Scot's sacking in April and saw the club finish seventh in the Premier League and fail to qualify for the Champions League.
Already 62-year-old Van Gaal, who has won titles with Ajax, Barcelona, AZ Alkmaar and Bayern Munich, is speaking in bullish terms.
Van Gaal said: "To work as a manager for Manchester United, the biggest club in the world, makes me very proud.
"This club has big ambitions
I too have big ambitions
Together I'm sure we will make history."
Van Gaal, previously linked with Tottenham, was installed as an early favourite for the position soon after Moyes' departure.
His vast experience of both winning trophies and handling top-level players, combined with his availability this summer, made him an attractive proposition.
Negotiations took time due to his commitments with Holland but the appointment has seemed inevitable for some weeks.
United executive vice-chairman Ed Woodward said: "In Louis van Gaal, we have secured the services of one of the outstanding managers in the game today.
"His track record of success in winning leagues and cups across Europe throughout his career makes him the perfect choice for us."
United striker Wayne Rooney took to Twitter on Monday evening to welcome his new boss to Old Trafford.
The 28-year-old posted: "Great to see Louis Van Gaal has been named @ManUtd manager
Looking forward to working with him.
"Congratulations also to Ryan Giggs on a special career and becoming assistant manager, I'm sure he will do a great job."
The elevation of Giggs from his previous role as player-coach is thought to have been a key part of discussions with Van Gaal
The club had been keen to retain the services of the most decorated player in the English game after he stepped in as interim manager for four games following Moyes' exit.
Giggs, who made his debut in 1991, said: "I am thrilled to have the chance to serve as assistant manager.
"Manchester United has been a huge part of my life and I'm delighted to be able to continue that relationship in such a key role."
In addition to Giggs, Holland goalkeeping coach Frans Hoek and coach Marcel Bout, a specialist in opposition scouting, will join the backroom staff.
As yet there has been no announcement from United concerning the future of Moyes' former assistants Phil Neville and Chris Woods.
Source : PA
Source: PA