| Conflict: | Battle of River Leça |
| Partof: | 1383–1385 Crisis |
| Date: | 1384 |
| Place: | River Leça, Portugal |
| Result: | Portuguese victory[1] Castilian attack on Porto stopped |
| Combatant1: | Kingdom of Portugal |
| Combatant2: | Crown of Castile |
| Commander1: | Pedro de Trastámara João Ramalho |
| Commander2: | Juan García Manrique |
| Strength1: | 6,800 men |
| Strength2: | 2,700 men |
| Casualties1: | Very Low |
| Casualties2: | Low [2] |
The Battle of Leça was a military encounter between a 6,800-man Portuguese force led by João Ramalho and Pedro, Count of Trastámara, a Castillian noble who was on the side of Portugal, and the smaller Castilian contingent led by the Archbishop of Santiago sent by John I of Castile to conquer Porto. The Portuguese forces, although smaller at the start, received significant reinforcements from Lisbon (that was also under siege at the time) just before the battle. The Portuguese attacked the Castilians who withdrew and were chased. Thus the Castilian blockade of Porto was finished.