Lupus (French: Loup, Leu; Welsh: Bleiddian; c. 383 – c. 478 AD) was an early bishop of Troyes.

Lupus retired to Macon where he came to the attention of Germanus of Auxerre, who appointed him bishop of Troyes.

In the autumn of 429, the Council of Arles, at the request of the bishops in Britain, sent Lupus and Germanus of Auxerre to combat Pelagianism.

[2] As such, Lupus is remembered in Wales as Bleiddian and appears in early Welsh Literature such as the Bonedd y Saint.

[7] According to the accounts, after praying for many days, Lupus, dressed in full episcopal regalia, went to meet Attila at the head of a procession of the clergy.

[8] However, the historical kernel it might contain is that Troyes was spared being sacked by Attila's army and that its inhabitants considered this a miraculous deliverance.