Volume I of the Warren Commission Hearings and Exhibits volumes is the first of 5 volumes of testimony taken by the Commission members in Washington DC. There are 10 additional volumes of testimony and affidavits taken by staff members in various locations, and 11 volumes of Exhibits.

Volume I consists largely of testimony by the Oswald family, including Lee Oswald's wife Marina, his mother Marguerite, and his brother Robert. This volume also contains testimony of James Martin, Marina's business manager for a short time in the aftermath of the assassination. The testimony in this volume was conducted between February 3 and February 27, 1964.