| Country: | DEU |
| Type: | B |
| Route: | 51 |
| Map: | B051 Verlauf.svg |
| Length Km: | 570 |
| Direction A: | North |
| Terminus A: | Bremen |
| Direction B: | South |
| Terminus B: | Kleinblittersdorf |
| States: | Bremen, Lower Saxony, North Rhine-Westphalia, Rhineland-Palatinate, Saarland |
The Bundesstraße 51 (translates from German Federal road, abbreviated as B 51) runs from Bremen in south-west direction though Lower Saxony, North Rhine-Westphalia, Rhineland-Palatinate and Saarland, and ends at the French border in the town Kleinblittersdorf.