My thesis re-situates the diarist and fiction writer Anaïs Nin within the fields of life-writing criticism, modernist studies, and intimacy studies by reading her diaries as performing, producing and inviting various intimate affects. This thesis focuses mainly on Nin‟s edited and unexpurgated published diaries and also draws on material gathered from the Anaïs Nin Special Collection at the Charles E. Young Library, based at the University of California, Los Angeles. Chapter 1 argues that Nin figures the diary as a space for fantasies of intimacy. Using the Communion as an integral part of these fantasies, Nin imagines scenes of interembodiment and intersubjectivity with her father that rely as much on his absence as on his presence. Performing an intimate relationship with her father, Nin also uses the diary to write her subjectivity as „in-relation.‟ Chapter 2 considers Nin‟s intimate relationships with other writers and artists in the 1930s, namely D.H. Lawrence. I argue that, by writing herself into an intimate relationship with Lawrence, Nin fashions and performs an artistic identity, working within and also resisting a modernist poetics of impersonality and objectivity. As such, this chapter calls for a revaluation of Nin as a modernist writer which attends to recent critical accounts of the importance of life-writing within modernism. Chapter 3 reads Nin‟s „Father Story,‟ an account in the diary of a brief affair Nin had with her father in her early thirties. I use the figure of seduction to argue that Nin‟s story resists a close reading and to critique various critical readings of this story in the 1990s which are underpinned by critical anxiety about the „right‟ way to read incest. For many critics, Nin‟s „Father Story‟ is too literary, rendering both it, and her, as inauthentic. Chapter 4 explores the intersections between Nin‟s diary and psychoanalysis. This chapter argues that Nin confuses the languages of sexual and psychoanalytic intimacy in ways that lead us to question the distance between sex and analysis. Nin uses psychoanalysis as another tool for dramatizing her life through art and another stage on which to perform intimacy. Chapter 5 considers the publication of the edited diary in the late 1960s-1970s, which coincided with a growing interest in women‟s life-writing as a representation of authentic, collective experience. This chapter argues that Nin performed intimacy in public with her readers, whilst all the time holding her private self at a distance.