Some critics have argued that William Butler Yeats and Irish Literary Revivalist defend nationalism in symbolic compensation in the form of mythologizing for the loss and trauma which result from the long history of the British colonial rule. Their focus has been the Celtic mythology and that of Mother Ireland. Other critics present their counter-argument by designating James Joyce as the precursor of the counter-movement which manifests the resistance against Yeatsian mythologizing among the exiled poets such as Beckett, Flann O’Brien, and Thomas MacGeevy, including Joyce. Establishing such polarity in the approaches to modern and contemporary Irish poetry in this way will produce a problematic logic which causes a secondary binary opposition between extreme nationalism and abstract cosmopolitanism. In attempts to avoid a futile reconciliation of the two arguments, one needs to redefine or deconstruct the master or grand narratives concerning myth, nation, and nationalism. Also, one might feel it necessary to provide a persuasive discussion of the interrelationship between myth and nationalism. Recent theorists such as Benedict Anderson, Lia Greenfield, Homi Bhabham, and Eric Hobsbawm have provided persuasive theories about nationalism and beyond-nationalism. Critics such as Tom Garvin, Desmond Fennell, Marianne Elliott, Roy Foster, Seamus Deane, Declan Kiberd, and Luke Gibbons have investigated the potential methodology to overcome the logic of binary opposition concerning Irish nationalism from the self-reflective perspective. The common ground of these critics and theorists is based upon the definition of nationalism in terms of what Benedict Anderson calls “imagined community” which is based upon the discursive anchors such as narrative, myth, and symbol. Irish national myth offers one of the most typical case study for this “imagined construction.” Using Richard Kearney’s term “post-nationalism,” the objective of this paper is to present a perspective of post-nationalism, and to demonstrate the polyphonic voices of modern and contemporary Irish poets, starting from Yeats and Joyce who have been approved among critics as the poets of the two mainstreams in 20th-century Irish poetry to those post-Yeatsian/Joycean poets such as Patrick Kavanagh, Austin Clarke, Thomas Kinsella, Seamus Heaney, and Derek Mahon, to name a few. My anchors of discussion are mythologizing, demythologizing, and remythologizing.