Mark O'Brien was an American writer known for his work in poetry, essays, and screenwriting. He gained recognition for his unique voice and perspective, often drawing from his personal experiences. O'Brien's writing often explored themes of disability, identity, and the human experience, making his work relatable to a wide audience. He is perhaps best known for his autobiographical essay, "On the Edge," which details his life with polio and his journey as a writer. O'Brien's contributions to literature have inspired many, and his work continues to be studied and appreciated in various literary circles, including those focused on disability studies.