E.I. Lonoff is a fictional character from the novel "The Ghost Writer" by Philip Roth. He is portrayed as a reclusive and celebrated author, known for his profound literary works. Lonoff serves as a mentor figure to the protagonist, exploring themes of creativity, identity, and the struggles of being a writer. In the story, Lonoff's character reflects the complexities of artistic life, including the tension between personal desires and public expectations. His interactions with the young writer reveal insights into the challenges faced by those in the literary world, making him a significant figure in Roth's exploration of the writing process.