The Unknown Quantity
- Leto: 1919
- Država: United States of America
- Žanr: Drама
- Studio: Vitagraph Company of America
- Ključna beseda: lost film
- Direktor: Thomas R. Mills
- Igralska zasedba: Corinne Griffith, Huntley Gordon, Harry Davenport, Jack McLean, Jack Ridgeway, F.R. Buckley