What do we read when we read King Lear? This essay argues that the answer is far from clear. Tracing the textual itinerary of Shakespeare's great tragedy by focusing on its beginnings (the Quarto History of King Lear of 1608 and the Folio Tragedy of King Lear of 1623) and its present (eleven scholarly editions which are currently in use), 'On Reading King Lear' demonstrates that each of these textual instantiations significantly differs from all the others and maintains that what we have access to as modern readers is not so much a single King Lear as many King Lears. What we read as King Lear today is thus in important ways a collaborative construction on which not only Shakespeare but also the modern editor has had a decisive impact.