We don't buckle to guilt or womanly sentiment. Everyone needs the strap across their back now and again. Teaches respect. You know that. You felt it. And look where it's gotten you.
~ Alistair Fitz speaking to his son.
Alistair Fitz is a supporting antagonist in the "Agents of Hydra" story arc in Agents of S.H.I.E.L.D.. He is the father of Leo Fitz, and in the framework he raised his son to be cruel, moulding him into The Doctor.
He was portrayed by David O'Hara.
In the real world, Alistair Fitz left his wife and son, and often called the latter worthless, however when his son was plugged into the virtual reality, the framework, created by Dr. Holden Radcliffe, he stayed with his son and molded him into becoming the cruel evil man that he was.
One day, Alistair informed his son that a security breach inside HYDRA had been discovered and that Project Looking glass was at risk.
While doing so, he found that his son seemed to be troubled and asked him to share a cup of tea. Alistair and his son then discussed the his son's position within HYDRA and when The Doctor started questioning his actions like when he a woman, Alistair quickly berated him and told him he had done the right thing. Afterwards, Alistair investigated the security breach.
When Jeffrey Mace was eliminated, Alistair toasted to the HYDRA victory over S.H.I.E.L.D. with his son and Madame Hydra.
Following the attempted assassination of Madame Hydra, Alistair told his son that he was now the new head of Hydra, whilst he lead chase after Agents May and Skye. Alistair reported the Subversives escape to his son, who became enraged. This made Alistair Fitz chastise his telling him his reaction was unworthy for what he taught him. The Doctor calmed down and told him that he couldn't accept failure, even from his father. Alistair then went to interrogate the locked up Holden Radcliffe and questioned him regarding the real world. When Radcliffe said that Fitz was a drunk who didn't recognize his own son's genius, he hit Radlciffe repeatedly, knocking him to the floor, demanding that he never talk about him or his son. All Fitz learnt from Radlciffe was that he had been speaking with Skye in the cell next door, and he mentions that Radcliffe doesn't have anything to live for. The Doctor then states that they make him have something to live for.
Whilst he was reading a book at his home, Jemma Simmons broke in, who started accusing him of his sons evil actions in this alternate reality. Simmons tells him to call his son, which he does telling him he loves him, but then tells the Doctor that Simmons is here, He then attempts to kill Simmons who shoots him.
It is unknown whether the Alistair Fitz in the real world is alive or not.