Noonan had moved to Cape Town, the capital of Britain's Cape Colony where he was a painter and decorator. When he married Elizabeth Hartel in October 1891, he was recorded as "Robert Phillipe Noonan, Decorator". A daughter, Kathleen, was born on 17 September 1892. In about 1894, Noonan moved to Johannesburg, with Kathleen, who lived in a convent boarding school. In Johannesburg, Noonan worked for the painting and decorating firm of Herbert Evans and seems to have had a foreman's job. During the 1890s a number of attempts were made to organise amongst British and other immigrant workers. One of them was the Trades and Labour Council (TLC), also known as the Transvaal Federated Building Trade Council. In the late 1890s, the organisation represented 'only the building trades, called together by Mr Noonan of Mssrs Herbert Evans and co'. It was in Johannesburg that he was drawn into socialist politics. He was elected to the committee of the newly formed International Independent Labour Party. Elected alongside Noonan was James Thompson Bain and it is possible that through Bain, Noonan was introduced to the socialist ideas of Robert Blatchford, and the political writings of William Morris, both thinkers that influenced the writing found in The Ragged Trousered Philanthropists. It is possible that Noonan acquiesced in a later notorious aspect of the labour movement in Johannesburg at this time: its support for movement towards racially-segregated workplaces, a policy supported by the Transvaal government at the time. In 1897, Noonan was granted a divorce, following an appearance as the plaintiff in a hearing at the Supreme Court, in Cape Town. The court granted the divorce and awarded Robert custody of Kathleen. It has been suggested that the failure of his marriage may have provided a sub-plot in The Ragged Trousered Philanthropists that concerns Ruth Easton, who has a child by Alf Slyme. He became active in the Irish Nationalist circle in the Transvaal. In 1898 Noonan became a member of the Executive Committee of the Transvaal '98 Commemoration Committee - established to arrange a celebration of the centenary of the Irish uprising. One of those who helped plan the Johannesburg commemoration was an Irish immigrant called Arthur Griffith, and serving on the committee was an assayer of the mine, John MacBride. The Boer government saw militant Irish Nationalism as a potential ally against the British. Noonan left Johannesburg shortly before the Boer War