A search for 'dragonlance' on ffn turned up five results in the Harry Potter section. Two in English, two in Spanish and one in French.

The English ones:
Challenge: HpDragonlance crossover
challenge HPxDragonlance with Raistlin and Mage!Harry

Dragonology
When a new professor arrives at Hogwarts, not only does he bring a new class with him, but a whole new world of creatures too, which leads to Draco discovering his owl is something he didn't expect. HP and Dragonlance Crossover Read and review please!