Mr. Robot is the leader of the hacker group called fsociety, and the first member of the group to meet Elliot. His real name is Edward Alderson, his hacker name is unknown, although he is revealed to be Elliot and Darlene's father; Mr. Robot is the nickname Elliot gives him. He is played by Christian Slater.
Biography
Fsocietyman
Monopolyman

As a child, Mr. Robot's father was never able to keep a job, and became a small time petty thief. Though his father bragged at least once about his exploits, garnering the young Mr. Robot's respect, he was eventually jailed and died soon after. In adulthood, Mr. Robot went on to become a computer hacker, and a member of fsociety.

Working with other hackers, like Darlene, Mr. Robot performed a number of attacks against E Corp. Knowing that Elliot worked for Allsafe Cybersecurity, which was responsible for E Corp's cybersecurity, Mr. Robot planted a message for him in an infected file on E Corp's servers, which he recieved after a large scale DDoS attack against E Corp. Following the attack, Mr. Robot approached Elliot and told him about fsociety's plan to take down E Corp. He then enlisted Elliot to plant evidence that Terry Colby, E Corp's CTO, was in fact responsible for the cyber attacks.

Elliot took Mr. Robot's nickname from the patch on his jacket, the name of a computer repair company. At times, Mr. Robot films videos presenting his manifesto to the business world, while dressed in a top hat, tails and mask, resembling the iconic Monopoly Man.

At the end of the first season we discover that Mr Robot is simply an Elliot Alderson's invention. He has been hallucinating his father and acting on the premise of orders from him, but has been leading fsociety the entire time.