Alan Dickinson, who spent 37 years at RBS, was chief executive of the UK unit during the bank's descent into state ownership.
Mr Dickinson was tasked with cutting 2,300 jobs and paring back the branch network in the wake of the bank's bailout, until he stepped down after little over a year in the job in mid-2009.
Before this, he spent several decades in RBS's corporate banking business. He joined Williams & Glyn, now folded into RBS, in 1973.
He has spent the last four years in non-executive posts including at Nationwide, where he chaired the building society's risk committee until last month.
"Alan's strategic focus and core banking experience complements the balance of skills on our board," said Lloyds chairman Lord Blackwell yesterday.
Mr Dickinson will leave his non-executive role at Carpetright ahead of his appointment at Lloyds on September 8. He also holds board seats at insurance firm Willis, private bank Brown Shipley and property developer Urban & Civic.