The 28-year-old has seen three previous world title fights against previous IBF champion Devon Alexander fall by the wayside because of injury isses, but now has the opportunity to make his mark on the big stage.
Porter, who is also unbeaten, beat Alexander to take the world title before demolishing Paul Malignaggi in four rounds in his last bout.
Brook's trainer Dominic Ingle said clinching the deal for the fight was a relief.
"It's been a long time coming and it feels like we've been waiting for this fight forever," Ingle told Sky Sports' Toe 2 Toe.
"His mind's firmily on the job and he's ready to go."
"Kell's been permanently fighting final eliminators and now the dream has become reality and Kell is well prepared.
"I'm surprised how well he's coped considering the carrot on the stick kept on getting dangled in front of him and then taken away. He's managed to maintain his focus - he's had three fights since the Devon Alexander fight fell through and he's trained well for each one and come through them.
"His mind's firmly on the job and he's ready to go."