The group said the closures will take place over a three to five year period as profits plunged at the struggling department store chain.
Debenhams swung to a £491.5m loss in the year to September 1 after being stung by exceptional write-downs of £512.4m, primarily relating to store and lease provisions, IT costs and impairment charges.
The loss compares with a £59m profit in 2017.
The firm's chief executive Sergio Bucher said: "It has been a tough year for retail in 2018 and our performance reflects that. We are taking decisive steps to strengthen Debenhams in a market that remains volatile and challenging.
"We are taking tough decisions on stores where financial performance is likely to deteriorate over time."
The store closures will bring the Debenhams estate down to about 100 and come on top of 10 earmarked earlier this year.
As part of the shake-up, Mr Bucher will look to take £130m of costs out of the business, including suspending the dividend.
Sales for the year slipped 1.8 per cent to £2.9bn while like-for-like revenue fell 2.3 per cent.
Mr Bucher said: "Debenhams remains a strong and trusted brand with 19 million customers shopping with us over the past year.
"With a strengthened balance sheet, we will focus investment behind our strategic priorities and ensure that Debenhams has a sustainable and profitable future."
A raft of retailers including New Look, Carpetright and Mothercare have also embarked on store closures programmes.
Debenhams is also the subject of takeover talk, with speculation building that Mike Ashley is set to merge it with his newly-acquired House of Fraser.
Mr Ashley owns just under 30 per cent of Debenhams, close to the threshold at which he must launch an official takeover bid.