Who Is Number One?
- Tahun: 1917
- Negara: United States of America
- Genre: Mystery
- Studio: Paramount Pictures
- Kata kunci: movie serial
- Pengarah: William Bertram
- Pelakon: Kathleen Clifford, Cullen Landis, Gordon Sackville, Neil Hardin, Bruce Smith, Ethel Ritchie
