Saint Æthelburh (died after 686x688) or Ethelburga, founder and first Abbess of the dual monastery of Barking, was the sister of Eorcenwald, Bishop of London.
The main source for Æthelburh is Bede's Historia ecclesiastica gentis Anglorum which recounts the foundation of Barking, early miracles there, and Æthelburh's death (Book IV, Chapters 6 to 10). Bede describes Æthelburg as "upright in life and constantly planning for the needs of her community".
A charter (Sawyer 1171), probably genuine and drafted by Bishop Eorcenwald in the reign of King Sebbi of Essex (reigned c. 664-c. 694), records a grant of lands in Essex by a certain Æthelred to Æthelburh and Barking. This is dated to between 686 and 688.
The 9th century Old English Martyrology records a vision, recounted by a nun of Barking, who saw Æthelburh being drawn up into heaven by golden chains. She was buried at Barking. The Old English Martyrology records her feast day as 11 October. Her successor as abbess was Hildelith.