Thompson (pictured) succeeds Sue Hayes, who is departing the bank.
Aldermore said the director of mortgages position would be open internally and externally, with the recruitment process beginning shortly.
“Aldermore always looks for the right talent to fulfil our roles. We will announce our new director of mortgages as soon as we appoint,” it said.
The lender pointed to its track record of promoting from within as when Claire Cordell was raised from director of finance to chief financial officer last September, succeeding James Mack who is to join Barclays UK as chief financial officer on 3 February.
“Damian’s appointment once again shows the depth of talent within Aldermore,” said Philip Monks, chief executive at Aldermore.
“Damian has made a significant contribution since he joined us, driving growth in our mortgage offering particularly in first-time buyer and buy-to-let markets.
“He’s a dynamic, knowledgable and well-regarded speaker on the mortgage sector. His appointment ensures we’ll continue delivering great products and service for retail customers,” Monks added.
Thompson joined Aldermore in 2017 on an interim basis and was appointed permanently in August 2018. He previously served at HBOS, Principality and Newcastle Building Society.