She replaces Rt Rev Jo Wells who became Bishop of Dorking in March.
Bishop Jo held the post for three years before becoming the South East's first female bishop.
Rev Hamley is currently a Biblical Studies tutor at St John's College in Nottingham and also an Associate Priest in the parish of Edwalton.
She will take up the new role in January.
Rev Isabelle Hamley:
Is originally from France
Has studied and ministered in Britain for twenty years
Is married to Paul and the couple have a daughter, Aelwen
Is currently finishing a PhD in Biblical studies called 'Relational identity, Otherness and Victimisation: An Irigarayan Reading of Judges 19-21'
Speaking about the appointment, Archbishop Justin said: "I am delighted to welcome Isabelle to the team at Lambeth.
"Isabelle comes to us highly commended by her diocese where she has served in several ministry roles, lay and ordained, in university, college and parish.
"She brings a pastoral heart, a spiritual richness and a rigorous theological understanding to what is a demanding role."
Rev Hamley said: "It is a privilege to join such a rich and diverse working environment, bringing my experience in parish, chaplaincy and theological education.
"I look forward to getting to know all those who work and live at Lambeth and enabling prayer to be the beating heart of our life together."
