Canon Gregory Cameron, 49, deputy secretary general of the Anglican Communion, succeeds the Rt Rev John Davies, who retired last month.
Canon Cameron, an expert in church law, was chaplain to Dr Rowan Williams when he was Archbishop of Wales.
The decision followed an electoral college of 47 people at St Asaph Cathedral.
Monmouthshire-born Canon Cameron gave a lecture in St Asaph last year when he addressed problems facing world anglicanism.
He said the Western church was in danger of adopting a NATO-style attitude of "intellectual superiority" over the church in the developing world.
The canon was ordained in 1984 and has held positions in parishes in Newport and Llanmartin in the diocese of Monmouth, and served as Dr Williams's chaplain for three years until 2003.
The electoral college took less than a day of a scheduled three days to come to a decision.
"I'm still absorbing the news, but as a Christian I really believe there's a gospel message to proclaim," said Canon Cameron.
He said he would be listening to the people in the diocese and had ideas he wanted to share.
Once elected, the bishop has up to 28 days to officially accept the position.He will become the 76th Bishop of St Asaph, an area covering the counties of Conwy and Flintshire, Wrexham county, the eastern part of Merionnydd in Gwynedd and part of northern Powys.
Read it all here. For more on Canon Cameron, click here for Brad Drell's excellent interview here and here. We also have our liveblogging of the Morning Press Briefing with Gregory Cameron during the Lambeth Conference in Canterbury, England, here.