The firm says that Mike Holliday-Williams, who will join Aegon on 1 October, will succeed Mr Grace who is to retire.
Aegon CEO Alex Wynaendts said: “I am pleased to announce the appointment of Mike Holliday-Williams as the successor of Adrian Grace
“Mike’s appointment signals Aegon’s continuing commitment to build on the strong foundation of our UK business.
“Mike brings extensive experience in the financial industry and a strong track record in focusing on customer solutions.
“I look forward to working with him.”
He added: “We would like to thank Adrian for having successfully modernised, transformed and repositioned our UK business.
“Under his leadership, our UK business has grown from £40bn of unit-linked pensions in 2009, to today where we oversee £175bn of pension and investment assets.
“We have repositioned Aegon to be the leader in the market of investment trading platforms and the company is now well positioned for further growth.
“We wish Adrian well in his deserved retirement.”
Mr Holliday-Williams said: “I am delighted to be joining Aegon at this pivotal time in our industry.
“I look forward to working with advisers to develop new solutions to enhance their relationships with their clients.”
Aegon says it intends to appoint Mike Holliday-Williams to its Management Board, subject to regulatory approvals.
Mr Grace will retire from the company on 31 March.