Kickham was born near Mullinahone, Co. Tipperary, the son of a draper, John Kickham. His mother, Anne O'Mahony, was a sister of John O'Mahony who played a prominent part in the insurrection of 1848 and founded the Fenian Brotherhood in America. The boy was educated at a local school and at home. At the age of thirteen, after a hunting trip, he sustained very severe injuries in an accident with a flask of gunpowder and, as a result, he became completely deaf. His eyesight was also seriously affected. For the rest of his life, he could communicate with others only by means of hearing aids, sign language and in writing. He could read only with some difficulty, holding the book very close to his eyes. In spite of this, such examples of his handwriting as exist appear to be reasonably legible. In his youth he was strongly under the influence of Davis, Duffy and the Young Ireland movement and was lastingly affected by the ideas promulgated in the movement's newspaper, The Nation. He became involved with William Smith O'Brien, John Blake Dillon and James Stephens, and played a leading part in founding a Confederate Club in Mullinahone. At the time of the abortive Rising of 1848 and the defeat at Ballingarry, Kickham went into hiding for a time, to escape arrest. Later, he became an active member of the Tenant Right League but seems gradually to have lost faith in constitutional agitation as a means for the righting of Ireland's problems. He wrote for a wide variety of nationalist papers, such as The Celt, ?The Irishman and The Nation. He became one of the principal contributors to The Irish People, the organ of the Fenian movement, and worked on it with O'Leary, Luby and O'Donovan Rossa.

He became a member of the Fenian organisation in 1860 and was a delegate to the Chicago Convention of 1863. In 1865, the government, well briefed by informers on Fenian affairs, swooped on the offices of The Irish People, suppressed the paper and arrested many of the prominent figures in the movement. Kickham escaped for a short while but was soon arrested, in company with Stephens. The trial took place in January of 1866 at Green Street courthouse, before the infamous Judge Keogh, and Kickham was sentenced to fourteen years imprisonment for treason felony. Confined first in Richmond Prison in Dublin, he was subsequently sent to Mountjoy Prison and from there to Pentonville. Then, on account of poor health, he was transferred to Woking Invalid Prison and was eventually released from there in March of 1869, having served a little over three years of his original sentence. Shortly after coming out of prison, Kickham was prevailed upon to stand for parliament in rather peculiar circumstances. Jeremiah O'Donovan Rossa, who was still in prison at this stage, was elected to parliament as member for Tipperary in 1869. His election was declared void and Kickham was then put forward in his place and came within four votes of winning the seat, being defeated only after a re-count. This was Kickham's last public political gesture but he continued to play an important part, with his friend, John O'Leary, in the activities of the Irish Republican Brotherhood, behind the scenes. Together, they continued to promote the pure Fenian doctrine of opposition to parliamentary agitation in any form.

In 1879, Kickham went to Paris with other members of the I.R.B., for a meeting with Michael Davitt, to discuss the 'New Departure' policy which advocated support for parliamentary activists. This meeting went badly partly because of Kickham's deafness, but the parties involved were, in any case, irreconcilable in their views. Davitt was to develop his policies through the Land League and Kickham continued to refuse to have anything to do with constitutional politics within a system which he saw as fundamentally corrupt. Irish politics were now to go the way of Davitt and Parnell. Kickham's failing health removed him from the centre of the stage. He retired to Blackrock, Co. Dublin, where he lived with friends until his death from a paralytic stroke in August, 1882. His body was taken in procession through the crowded streets of Dublin with considerable public honour and he was buried in his native place, Mullinahone. The impression of him which survives is of a gentle, idealistic figure, opposed to violence and filled with a deep love of his own Tipperary locality. When he was asked what he had missed while in prison, he answered memorably, 'Children, and women and fires'. He cherished a romantic notion of Ireland's struggle and was not prepared to promote his political views by violent guerilla tactics. Of all the Fenians, he appears to have been closest in spirit to the ideals of those earlier patriots of the Young Ireland movement. Although some of his contributions to The /rish People were of an anti-clerical tone, in that they attacked the Irish hierarchy's support for the status-quo, he nevertheless remained an ardent Catholic all his days. When John O'Leary's sister asked him whether he had prayed much in prison he produced yet another quotable reply by telling her that he had said in prison exactly the same prayers as when he was free. In addition to his prose fiction he wrote some of Ireland's best-loved ballads, among them such loved favourites as 'The Irish Peasant Girl' (i.e. 'She Lived Beside the Anner') and 'Rory of the Hills'. From the Appletree Press title The Anglo-Irish Novel vol. 1 - The Nineteenth Century by John Cronin.