This thesis considers the hitherto unexplored question of modernism and non-fictional genres. Although modernist studies have long been attentive to the implications of modernism's "manifestos", and recent work on modernist magazines has shed new light on forms beyond poetry and fictional prose, little attention has been afforded to other non-fictional writing. Similarly, although a growing school of criticism has emphasised the significance of "the everyday" in modernist texts, few have examined non-fiction concerned with leisure or daily life - a particularly unusual omission given the rich possibilities such texts offer for our understanding of how everyday lives relate to wider society. This thesis examines instructional texts which make radical interventions in the social and political upheavals which follow the First World War. Contra to the well-debunked yet still pervasive narratives which typify the modernist text as a work of disinterested - even isolated - genius, these examples demonstrate a broad-ranging, complex engagement with popular venues. Surveying examples of popular genres such as cookbooks, travel guides and radio programs written by a range of canonical and lesser-known modernist writers, it demonstrates how modernist writers re-appropriated the common features of such mainstream forms in order to stage various (and varied) interventions in local and national affairs. Its reading of Sylvia Townsend Warner's Somerset (1949) and Scottish Scene: The Intelligent Man's Guide to Albyn (1934), by Hugh MacDiarmid and Lewis Grassic Gibbon, shows how adopting the "textual codes" of travel guides provided authors with a means of writing back against the over-simplistic narratives of region and nation popular in other examples of the genre. Likewise, The Alice B Toklas Cook Book (1954) and F.T. Marinetti's The Futurist Cookbook (1932) are read as divergent examples of texts which stage radical interventions in food practices as they relate to nationhood and conflict. Comparable interventions are also unearthed in the media. Flann O'Brien's Cruiskeen Lawn columns (1940-66), published under the name Myles na gCopaleen, are often read in studies of Irish political and cultural consciousness. This thesis argues that they must also be read in terms of genre, demonstrating how a subversive use of headlines, bylines and other page architecture signals O'Brien's use of the newspaper form itself to pass comment on the cultural and political life of the Republic of Ireland. Finally, this thesis turns to broadcast culture, with a chapter on radio and documentary films. Through readings of Virginia Woolf and Elizabeth Bowen's radio broadcasts, and the GPO Film Unit collaboration of Benjamin Britten and W.H. Auden, this chapter shows how irony and experiment allowed writers to turn state-sanctioned media to their own ends during the interwar years - suggesting that literary readings are crucial to understanding modernism's engagement with new media. Through these different readings, this thesis highlights the sheer diversity of modernist genres which have either received little critical attention, or whose formal specifics have been under-acknowledged. As a result, it is able to reframe modernism's approach to several areas of twentieth-century life, approaching anew pressing areas of concern in the field - for instance, space and place, the circulation of texts, the everyday, and the commercial, lowbrow and domestic - demonstrating the critical importance of instructive genres to understanding literary modernism.