True History of the Kelly Gang gives the bushranger Ned Kelly a chance to tell his own story in the form of a long letter to his daughter in San Francisco. Kelly’s father was a former convict, transported to Tasmania; Kelly has no idea what his father’s crime might have been. He met Kelly’s mother, Ellen, in a town called Donnybrook, and they determined to marry. Her family, the Quinns, were habitual criminals who constantly drew the attention of the police. Ellen Quinn was unaware that her husband was a former criminal, but the police knew, subjected his family to much attention, and attempted to blackmail Ellen for sexual favors. Kelly’s father is finally imprisoned when he takes the blame for young Kelly’s theft and butchering of a cow, although he is in fact prosecuted for removing a brand from the hide. He is released as a favor after Kelly saves a local man’s son from drowning, but he is a broken man and dies shortly after.

At twelve, Kelly finds himself the man of the family and struggles to lead a law-abiding life through farming and breaking horses. His mother, meanwhile, opens a drinking den and, it is suggested, also works as a prostitute. The family moves around, supported by the extended Quinn family, finally settling in the Glenrowan area, where they have bought some land and become “selectors,” or settlers. However, they live in great poverty and remain targets for the local police. Young Ned is temporarily apprenticed to the bushranger Harry Power and is present when a number of crimes are committed. He serves several terms in prison for alleged cattle-rustling and other crimes.

The final period of his short but tumultuous life begins with an incident on the family property, when a policeman, Fitzpatrick, claims he was injured in a gunfight with members of the Kelly family. The Kelly family claim Fitzpatrick was knocked to the ground when he attempted to proposition Ned’s sister Kate. Ned’s mother is imprisoned, but Ned and his brother Dan go into hiding, where they are joined by two friends.

The police determine to track down the Kelly gang. Ned and his friends come across a group of police officers at Stringybark Creek, whom they disarm, killing one policeman, and then wait for the others to return. When they do, although one policeman proposes that the police should surrender, the others refuse, and there is a shootout in which all of the policemen are killed.

The Kelly gang then carry out a series of audacious bank raids, taking hostages but killing no one. They are finally betrayed by one of their friends when they arrive in Glenrowan. Knowing that a trainload of policemen is on its way to the town, the gang take hostages and pull up rail tracks in order to cause a train crash.

Ned Kelly’s letter to his daughter ceases at this point, and his story is supplemented by a third-party account of the siege in which the Kelly Gang, all except Ned, are killed, and an account of Ned Kelly’s hanging.

Throughout the narrative, Kelly is desperate to ensure that his daughter knows the truth about her father, and he attempts to justify his actions, as he did in the Jerilderie letter, by showing that the police and the authorities in Victoria treated the colonists unfairly and with great severity.