In 1838, Smiles was invited to become editor of the Leeds Times. He was also a strong supporter of the co-operative movement in Leeds, especially the Leeds Mutual Society and the Leeds Redemption Society. In 1840, he became secretary to the Leeds Parliamentary Reform Association, supporting the views of Chartism. Although an original supporter of Chartism, Smiles became alarmed by the growing militarism of some of the leading Chartists. Therefore, he began to distance himself and became the secretary to the newly formed Leeds and Thrisk Railway.