The Wales international has spent a combined nine years in East London, either side of a three-season spell with Aston Villa between 2009 and 2012.
Collins turns 34 next month and is now into the final year of his latest contract, but he is hopeful of staying in place beyond the end of next summer after a strong end to the 2016-17 campaign when filling in for crocked teammate Winston Reid.
"To think I've been a part of this club for nearly ten years now is incredible," he told the club's official website. "It's been a major part of my life - I met my wife here, so my family are from the area, and I'm a very lucky boy to have been at such a good club for so long. And hopefully it can continue.
"I'd love to finish my career here. I'm 33 now, but I felt at the end of last season that I was playing as well as I ever have. I've come back for pre-season fit, I'm lucky that I haven't had any really major injuries in my career, and I feel really good. I'm going into the last year of my contract, but I believe there is a lot of football left in me at this level and I'd love to stay here for years to come.
"I was delighted with the way I was playing towards the end of last season. I came into the team when we were still looking over our shoulders a little bit. We steadied the ship, though, my form was good and, to be honest, I was a little bit gutted to be going off at the end of the season - I would have liked it to carry on a bit longer! I've kept my fitness over the summer, though, and I'm really looking forward to the new season."
Collins could make his 200th appearance in all competitions for United if selected to play against Manchester United on the opening weekend of the Premier League season.