Crouch told the club's website: "I was only a young kid when I was here before and a long way from the player I am now.
"I think Ledley (King) is the only player still here from when I was here before. I'm looking forward to seeing him again because I've always kept in touch with him all those years.
"I remember watching the likes of Ginola, Anderton, Sheringham and Ferdinand every week on the terraces with Ledley and it's great to finally be getting the chance to play for this Club.
"Now I bring with me the experience of having played in the Champions League and at a World Cup for England.
"From my point of view, it's not just about coming back, it's about joining a massive football club which has no limit to where it can go."
Crouch's move to north London will also provide a reunion with Harry Redknapp, who he worked under during a successful campaign at Southampton, as well as for the early part of last season at Portsmouth.
"The manager has got a lot of faith in me and believes in my ability to be a top player," said Crouch. "He always tells me that and, whenever I play for him, he seems to get the best out of me.