The focus of this research is the critically neglected comic strip work produced by the Irish painter Jack B. Yeats for a number of British publications between c. 1893 and 1917. The thesis seeks to identify and analyse the corpus of his previously unexamined work, positioning it in relation to contemporaneous media, entertainment and popular culture, as well as to the early development of the British comic. This thesis seeks to establish the key role that Yeats played in the early development of the form, during a key phase in its evolution. The claims that the thesis makes for Yeats as an important comic strip artist are based on extensive archival research, focused on comics such as Comic Cuts, The Big Budget and The Halfpenny Comic published in London by Alfred Harmsworth, Arthur Pearson and George Newnes respectively. He went through a number of identifiable phases in terms of his graphic style, producing a very substantial volume of work over the course of his career, largely in the form of series of strips featuring recurring characters, a number of which became very popular with the reading public. Yeats has almost exclusively been discussed in terms of his fame as a fine artist, despite the fact that his comics work was widely disseminated during his lifetime. Given that the work was once well known, as part of a novel and widely circulated mass medium, it is necessary to interrogate the absence of this material from art-historical accounts of his work and reassess Yeats as a comic strip artist. In Ireland there has been a tendency to articulate Yeats in terms of national identity, and thus avoid recognition of his engagement with, and contribution to, British popular culture. Issues regarding the mutual exclusivity of the ‘high’ and ‘low’ cultural registers in which he operated has likewise resulted in the valorization of a particular area of his creative activity and the exclusion of the material acknowledged, discussed, and celebrated here. The repositioning of Yeats in relation to comic strip art has profound implications for the study of twentieth century Irish art generally, and for Yeats connoisseurship specifically, and proposes significant challenges to both, as well as making a contribution to British comics history.