Mr Lawson will report to Graham Boffey, managing director of Aviva's corporate benefits business. Aviva said this was a new role.
Mr Lawson has worked at Standard Life since June 2001, having previously worked at Bank of Scotland.
Mr Boffey said: "I'm delighted that John Lawson is joining the Aviva team at a time when our workplace business is gaining significant momentum. As head of policy, John will use his industry expertise and insight to further shape our end-to-end corporate benefits business to ensure we get it right for our customers.
"The workplace market is evolving swiftly, driven by pension reform and the changing demands of employees and employers - I am confident John will strengthen Aviva's voice at this critical time."
Nicola McGowan, spokesperson for Standard Life, said Mr Lawson had already left the company ahead of his move in January. She said the firm had not made a decision on whether he would be replaced yet but that the firm had a team of pensions experts so it was "business as usual".
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