He will lead a 40-strong comms team at the FSA, where he replaces Neil Martinson, who quit five months ago to start his own agency.
'We need to make sure the FSA works in partnership with industry.
It's no use being at loggerheads,' he said.
The FSA was created as an independent government department in 2000 after the BSE crisis. Its remit is to protect public health and consumer interests.
This week critics claimed it had caved in to pressure from supermarkets and food manufacturers and reneged on its salt reduction targets. The FSA had decreed that by 2010, a 110g serving of crisps would contain no more than 1.4g of salt, but this has been raised to 3.4g.
Collis will report to John Harwood, who was announced as the FSA's interim chief executive this week. Harwood, who established the Learning and Skills Council for England, replaces Jon Bell, who leaves at the end of this month when his contract expires.
Collis was made redundant as Lloyds TSB director of group corporate comms last April, having held the role since 2000. Prior to that, he was director of corporate comms at National Westminster Bank.
Since leaving Lloyds TSB, Collis has engaged in charity work for the Red Cross.