Sir Alex Ferguson:
"I was never too big or proud to ask him for advice which he gave freely and unconditionally. In my 23 years working in England there is not a person I would put an inch above Bobby Robson.
"I mourn the passing of a great friend; a wonderful individual; a tremendous football man and somebody with passion and knowledge of the game that was unsurpassed."
"The death of Sir Bobby is a sad loss to football. His record in many different countries was testament to his talents as an outstanding manager, and he clearly never lost his tremendous passion and enthusiasm for the game."
"He will be sadly missed by everyone, not just by people in the football world but from all walks of life. It's a very sad day for everyone, especially his family, his close friends and anyone who's ever worked with him."
"He was a fantastic football manager, probably the most enthusiastic football man I've ever met in my life. Look at the job he did at Ipswich, and all over the world. I've never met a man with more enthusiasm and passion for football."
"Sir Bobby was a wonderful man, a real gentleman. His spirit and courage was incredible. To fight cancer so many times really showed the strength of the man."
"We had some great times. He was just a pleasure to work with. I was with him in Portugal only a few weeks ago when I went over to play in his charity golf day which was a fantastic event.
"He was struggling with illness at the time and had been advised not to travel, but he wanted to be there. That just shows the character of the man."Glenn Hoddle:
"For everybody in the football world it's a very, very sad day. He's the closest we've come to winning the World Cup (since 1966) - that's how good Bobby was.
"I met up quite a few times with him when he was Newcastle manager and that passion was still there. I think that was still there to this very day. He had a genuine, refreshing love the game."
"He had a tremendous enthusiasm and passion for football and life and continued to retain this right to the last days of his life.
"He will be deeply missed by everyone, especially those who played for him. I have the fondest memories of playing for him at two World Cups."Terry Venables:
"It's really sad and I am really hard put to a few words together. We came across each other many times, on TV for World Cups, and we played against each other. We go back far and we had some great times. I feel now for Bobby's family."
"Sir Bobby was like a father to me, taking a personal interest in me right from the start, always checking whether I was happy. His support and enthusiasm was the perfect cure for homesickness and helped my career to get off the ground and thrive.
"I could not possibly get my head round how my career would have gone had it not been for Sir Bobby Robson. I owe him everything and I only hope I can be guided by the example he showed me."
"Everyone had the utmost respect for him. He handled people in the right fashion and I think that was his major strength. He was a joy to be around."