The England international shot to fame at Old Trafford under the management and guidance of the Scot before joining Spanish giants Real Madrid for £25million.
His move to the Spain came shortly after an infamous event when Ferguson unintentionally kicked a boot at him, causing a cut that needed two stitches over his eye.
But Beckham has put that incident behind him and gave his former manager a glowing testimony.
"It's been amazing. But that's what happens when you have stability, and a man that is so passionate and hungry, who has the love for one club that he has," the 36-year-old said in the special tribute magazine created by United Review.
"That loyalty and respect for one club is unbelievable and it's not something you see these days.
"It says a lot about United as a club and the manager."
"It's 50/50 with my parents - that's how highly I regard the boss.
"My parents were the ones who brought me up and helped get me to a certain level in my career, and the manager is the one who took me to a whole different level.
"He's the sole reason why I was successful. He gave us everything we needed to become the players and the men that we are today."
Beckham won six Premier League titles, two FA Cups and a Champions League title during his 10 year spell with the Red Devils.