Odo of Bayeux (died 1097), Earl of Kent and Bishop of Bayeux, was the half-brother of William the Conqueror, and was, for a time, second in power after the King of England.
Odo was the son of William the Conqueror's mother Herleva and Herluin de Conteville. Count Robert of Mortain was his younger brother. There is uncertainty about his birth date. Some historians have suggested he was born around 1035. Duke William made him bishop of Bayeux in 1049. It has been suggested that his birth was as early as 1030, making him about nineteen rather than fourteen at the time.
Although Odo was an ordained Christian cleric, he is best known as a warrior and statesman, participating in the Council of Lillebonne. He found ships for the Norman invasion of England and is one of the very few proven companions of William the Conqueror, known to have fought at the Battle of Hastings in 1066. The Bayeux Tapestry, probably commissioned by him to adorn his own cathedral, appears to labour the point that he did not actually fight, that is to say shed blood, at Hastings, but rather encouraged the troops from the rear. The Latin annotation embroidered onto the Tapestry above his image reads: "Hic Odo Eps [Episcopus] Baculu[m] Tenens Confortat Pueros", in English "Here Odo the Bishop holding a club strengthens the boys". It has been suggested that his clerical status forbade him from using a sword, though this is doubtful: the club was a common weapon and used often by leadership including by Duke William himself, as also depicted in the same part of the Tapestry. Odo was accompanied by William the carrier of his crozier and a retinue of servants and members of his household.
In 1067, Odo became Earl of Kent, and for some years he was a trusted royal minister. On some occasions when William was absent (back in Normandy), he served as de facto regent of England, and at times he led the royal forces against rebellions (e.g. the Revolt of the Earls): the precise sphere of his powers is not certain. There are also other occasions when he accompanied William back to Normandy.