Mitchell, 25, will fight Aussie slugger Michael Katsidis on May 15 with the interim version of the belt on the line.
But the Hammers nut is likely to end up going for the full crown with current champ Juan Manuel Marquez expected to vacate.
And Mitchell, wearing a replica of the West Ham's shirt from the 1964 FA Cup final triumph over Preston, admitted: "This is absolutely crazy.
"I never thought it would happen. On May 15, not only do I get the chance of a world title but it's happening at the football club I love.
"I grew up watching West Ham play and if I hadn't been a boxer I would have been a footballer.
"I think one of my proudest moments was being introduced to the fans down here before a game the other week and getting an amazing reception.
"But now I'm going to be fighting here and I still can't quite believe it.
"The fans in the East End are very special people. To get the opportunity to fight in front of them is a dream come true."
Amir Khan fights on the same night in New York, where he will defend his WBA light-welterweight crown against Paulie Malignaggi at the 5,000 capacity WaMu Theatre at Madison Square Garden.
Mitchell, meanwhile, has gone full circle from his days fighting in a vest.
The 25-year-old Dagenham Destroyer added: "My first ever amateur fight was just around the corner from Upton Park at the East Ham Working Man's club when I was just 11 and representing Hornchurch ABC.
"Now I'm back to fulfil my destiny of becoming a world champion and I am not about to fail in front of a crowd that could be anything up to 30,000.
"My phone has already gone mental with mates ringing for tickets.
"I want to walk to the ring with the Hammers theme song of Bubbles playing and my all-time West Ham hero Julian Dicks will be with me.
"I'm told Marquez will be vacating the title because he will be moving up in weight and that leaves me and Katsidis to decide who is the next champion.
"I've never underestimated any opponent and I certainly won't underestimate Katsidis. He's a tough, strong and competitive fighter who will never stop throwing punches.
"But I really do think I will have too much power for him and that will be what stops the fight going the distance."
Promoter Frank Warren said: "Right now the fight has interim world status but I'm certain it will be for the full vacant title by the time fight night comes around on May 15.
"This will be the first world title fight staged at West Ham.
"It's the first world title fight held at a major football stadium in London for years and I'm sure East Londoners will turn out in force to roar on Kevin."
Tickets for Mitchell v Katsidis are available on 0871 222 2700 or 0871 2200 260.
