Bruce Wayne / Batman
Batman returns for the first time in eight years since Harvey Dent's death. He has taken the blame for Dent's murder in order to put the power back into the hands of the police to clean up the streets. But with the introduction of Bane to Gotham City he comes out of hiding to stop the madman from achieving his plan of complete destruction of Gotham.
Bane
A mercenary and a member of The League of Shadows that has come to Gotham in order to fulfill Ra's Al Ghul plan of destroying the city he considered a plague. He is Miranda Tate's protector as she is Ra's Al Ghul's daughter. He has lived a life of pain and torture that is subdued by a mask which keeps his pain at bay.
Miranda Tate
Miranda Tate is after clean energy for Gotham and desires for Bruce Wayne to turn on the nuclear reactor that he purchased to do so. But he won't as if it falls into the wrong hands it could be used as a nuclear weapon. When Bruce is voted out as Chairman of his own company, Tate is elected the new Chair. But, she has hidden her identity as Ra's Al Ghul's daughter who has waited for decades to exact her revenge on Bruce Wayne and Gotham city in order to fulfill her father's destiny for the city.
Blake
Blake is a beat cop that becomes a detective once Bane begins to take over the city. He is an orphan who was helped by Bruce Wayne's generosity as a kid, and knows that Wayne is Batman. He works with Commissioner Gordon to find a way to stop Bane. In the end, he is revealed to be Robin.
Selina
Selina is Catwoman in Nolan's film. She is a high level thief that is seeking to wipe her identity clean in order to have all of her felonies removed from her record and start a new life. She is caught between doing the right thing and saving her own neck throughout the story, but when it comes time to come through she is there for Batman even after she's betrayed him.
Commissioner Gordon
Commissioner Gordon is taken hostage by Bane's men before escaping their captivity with a serious gunshot wound. He recovers in the hospital and trains up Blake to be his eyes and ears while he is unable to leave due to his injuries. It's discovered that Gordon has lied to the people of Gotham about Harvey Dent's death and his secret will finally come out into the open.