Willoughby, John de I Baron Willoughby of Eresby
| Birth Name | Willoughby, John de I Baron Willoughby of Eresby |
| Gender | male |
| Age at Death | about 48 years |
| Birth date | about 1152 (Grimsthorpe Castle, Willoughby, Eresby, Lincolnshire, England) |
| Death date | 1200 (Willoughby, Lincolnshire, , England) |