Sæberht, Saberht or Sæbert was an Anglo-Saxon King of Essex, in succession of his father King Sledd. He is known as the first East Saxon king to have been converted to Christianity.

The Kingdom of the East Saxons, referred to as the Kingdom of Essex, was one of the seven traditional kingdoms of the Anglo-Saxon Heptarchy. It was founded in the 6th century and covered the territory later occupied by the counties of Essex, Middlesex, much of Hertfordshire and west Kent. The last king of Essex was Sigered of Essex, who in 825 ceded the kingdom to Ecgberht, King of Wessex. From 825 Essex was ruled as part of a south-eastern kingdom of Essex, Kent, Sussex and Surrey. It was not until 860 that Essex was fully integrated into the crown of Wessex.