John I, Duke of Brunswick-Grubenhagen
| John I, Duke of Brunswick-Grubenhagen | |
|---|---|
| Born | before 1322 | 
| Died | 23 May 1367 | 
| House | House of Guelph | 
| Father | Henry I, Duke of Brunswick-Lüneburg | 
| Mother | Agnes of Meissen | 
John I, Duke of Brunswick-Grubenhagen (before 1322–23 May 1367) was provost of the St. Alexandri Minster in Einbeck.
He was the son of Duke Henry I "the Marvelous" of Brunswick-Grubenhagen and his wife Agnes of Meissen, daughter of Margrave Albert II of Meissen.