He was 58.
The college said his passing for sudden and unexpected.
It says it's clinging to the promise that "for God so loved the world that he gave his only Son that whoever believes in him should not perish but have eternal life".
It's asking Christians to pray for Mike's wife Heather and their three children Charlie, Harry, and Ana.
Details about his funeral and thanksgiving will follow in the coming days.
Archbishop of Canterbury Justin Welby has been leading the tributes on social media, describing his death as a great loss to the Church.
So sad to hear of the death of Mike Ovey of Oak Hill College. Please pray for family & friends and for the College. Great loss to church.
— Justin Welby ن (@JustinWelby) January 8, 2017
Bishop of Burnley Rt Rev Philip North described him as a "wonderful man" while Bishop of Willesden Rt Rev Pete Broadbent said he was "a man of great faith, conviction, clarity and integrity".
Such sad news about Mike Ovey's death. Prayers for his family and all @OakHillLondon. A wonderful man.
— Bishop Philip (@BpBurnley) January 8, 2017
Great shock to hear this. Prayers for his family and the whole Oak Hill community. A man of great faith, conviction, clarity and integrity. https://t.co/2RJC1U9IDe
— Pete Broadbent (@petespurs) January 8, 2017
Mike Ovey was a civil service lawyer before training for ministry at Ridley Hall, Cambridge. He worked as a curate for four years at All Saints, Crowborough, before teaching for three years at Moore Theological College, Sydney.
He joined Oak Hill in 1998 and since then has finished a PhD in the field.
He contributed regularly to Premier Christianity magazine.